JP2003258719A - Wireless communication system, base station, relay station, mobile station, and packet transmission control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat a signal collision in a conventional CSMA or TDMA multi-hop scheme as a tolerable interference by applying a CDMA scheme, to group a group of channels in multi-hop transmission, and the like. By performing transmission control based on the interference level from the station, the hidden terminal problem and the like are reduced and the throughput of the entire system is improved. For example, a multi-hop relay station calculates a desired signal level from its own interference level of a packet transmitted from a mobile station, notifies the mobile station of the desired signal level. Calculate the transmission power amount of the packet from the signal level, determine whether to transmit the packet to the desired signal level notification source station from the transmission power amount, and provide the power of the transmission power amount to the notification source station determined to be possible. Is used to transmit a packet. At this time, interference signals are reduced by assigning a plurality of channel groups 1 and 2 used for signal transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system, a base station, a relay station, a mobile station and a packet to which a multi-hop technique for connecting a mobile station and a base station using multi-stage relay by a relay station is applied. The present invention relates to a transmission control method.

In the radio communication system according to the present invention, there are three stations, "base station", "relay station" and "mobile station", as stations involved in one communication. In the following, the "base station" is a core network. Stations that can be connected to other base stations via
The “mobile station” is the terminal that first requests the packet transmission or receives the packet last (that is, the packet destination), and the “relay station” relays the packet from the mobile station to the base station or from the base station. The terminals having the function of relaying the packet of 1 to the mobile station are meant respectively.

The "packet transmission direction" is a generic term for the "uplink direction" from the mobile station to the base station and the "downlink direction" from the base station to the mobile station in the above wireless communication system. In the following, "upward direction",
The “downward direction” is also used in the above meaning. Further, the "hop number" is the number of times that relay is performed by a station existing between the station that is the origin of the transmitting side and the station. For example, in the case of upstream communication, the number of times that a mobile station or a relay station existing between a base station and a mobile station performs relay when the mobile station communicates, In addition, the number of hops of the base station is 0, the number of hops of the mobile station capable of direct communication is 1, and the number of hops of other mobile stations or relay stations is increased by 1 each time relay is performed. is there. The number of hops in an embodiment of the invention described below is the number of times the relay is performed by the mobile station or the relay station existing between the base station and the mobile station when the mobile station communicates. Means "indicated number of times". Also, in the case of downlink communication, when the base station communicates,
It is the number of times that relay is performed by a base station or a relay station existing between a base station and a mobile station.

[0004]

2. Description of the Related Art In a conventional cellular mobile communication system, a mobile station participates in a network by selecting a base station having the highest reception level at that time and directly communicating with the base station. At that time, if the reception level from the base station does not reach the required value even when the maximum power is transmitted,
The mobile station cannot establish communication with the base station.

In order to solve this problem, a multi-hop method has been proposed in which, when direct communication with the base station is not possible, another mobile station is relayed to communicate with the base station. For example, in FIG.
Although the mobile station 14 shown in FIG. 2 can directly communicate with the base station 12, the mobile station 11 cannot directly communicate with the base station 12 because of an obstacle 15 between the mobile station 11 and the base station 12. At this time, another mobile station 13 having a relay function acts as a relay station, and the mobile station 1
This is a technique for realizing communication between the mobile station 11 and the base station 12 by relaying communication between the mobile station 11 and the base station 12.

[0006] Such a multi-hop system enables communication of mobile stations located in areas where the radio waves of the base station cannot reach, thus simplifying station placement which was difficult due to buildings or terrain. In addition, in the conventional method, it is necessary to cover all the service area only with the cell area of the base station, but by introducing the multi-hop method, even if there is a gap between cells, the mobile station can be Since it becomes possible to communicate, it is possible to reduce the number of base stations,
This will reduce the cost required for network construction.

However, in the CSMA-based multi-hop schemes that have been proposed so far, there is a so-called hidden terminal problem (because adjacent stations transmit signals at the same frequency, the overlapping areas of the wireless zones of these adjacent stations are The problem that the station located cannot receive due to the collision of both received radio waves (for example, the paper titled "Does IEEE 802.11 MAC protocol wo" published in "IEEE communication magazine (2001)".
rk well on multihopwireless ad-hoc networks ", author: Shugong Xu, et. Al. It was a solution.

[0008]

As described above, in the conventional cellular mobile communication system, the range of the service area is greatly affected by the arrangement of the base stations, and the mobile station communicates in the area where the reception level of the radio waves of the base station is low. There was a problem that could not be established. In addition, conventional CSMA and TD
The multi-hop method using the MA method is promising as a means for enabling the above-mentioned incommunicable mobile stations to communicate, but depending on the arrangement of relay stations, a hidden terminal problem or the like may occur, resulting in an increase in traffic and a decrease in system throughput. Was invited.

The present invention has been made in order to solve the above-mentioned problems, and while avoiding an increase in traffic and a decrease in system throughput, the mobile station communicates more reliably regardless of the arrangement of relay stations. It is an object of the present invention to provide a wireless communication system, a base station, a relay station, a mobile station, and a packet transmission control method capable of establishing a packet.

[0010]

In order to achieve the above object, a radio communication system according to the present invention includes a base station, a mobile station, and a relay station having a relay function for packet transmission by multihop. In the wireless communication system configured to perform communication based on the wireless packet transmission method, the receiving side station in the packet transmission has an interference level measuring unit that measures an interference level when receiving a packet, and obtains by the measurement. Desired signal level calculating means for calculating the desired signal level based on the interference level, and a desired signal level notifying means for notifying the calculated desired signal level to the transmitting station, the transmitting station, Transmission power amount calculation means for calculating the transmission power amount of the packet based on the desired signal level notified from the receiving station, and the transmission power amount calculation means. Based on the amount of transmit power, characterized by comprising determination means for determining whether the packet transmission to the station of the recipient. It should be noted that in a certain aspect of packet transmission, all of the base station, mobile station, and relay station may be the “receiving side station”. Similarly, each of the base station, mobile station, and relay station may be the “transmitting station”.

That is, at the receiving station in packet transmission, when receiving a packet, the interference level measuring means measures the interference level, and the desired signal level calculating means calculates the desired signal based on the interference level obtained by the measurement. Calculate the level,
Then, the desired signal level notification means notifies the calculated desired signal level to the transmitting station. In the station on the transmission side, the transmission power amount calculating means calculates the transmission power amount of the packet based on the notified desired signal level, and the judging means determines to the receiving side station based on the calculated transmission power amount. Whether or not the packet transmission of is possible is determined. In this way, based on the interference level at the receiving station, the transmitting station performs packet transmission control by searching for a connection destination and determining whether or not packet transmission is possible. As described above, the transmitting station receives the notification of the desired signal level obtained based on the interference level of the receiving station, calculates the transmission power amount of the packet based on the desired signal level, and calculates the calculated transmission. Based on the amount of power, it is determined whether or not the packet transmission to the receiving station is possible, so that it is possible to realize an appropriate packet transmission availability determination according to the interference level of the receiving station, and regardless of the arrangement of the relay station, It is possible to avoid problems such as a hidden terminal problem, an increase in traffic, and a decrease in system throughput.

[0012] In the above wireless communication system, the CSMA / CD system is used to judge whether packet transmission is possible based on an interference signal instead of the interference level in that packet transmission is judged according to the interference level of the receiving station. It has different characteristics.

The wireless communication system according to the present invention is
A wireless communication system configured to include a base station, a mobile station, and a relay station having a relay function for packet transmission by multi-hop, and performing communication based on a wireless packet transmission method, the receiving side in the packet transmission. When receiving a packet, the station of the above, interference level measuring means for measuring the interference level, desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, the interference level, the desired Determination means for determining whether or not packet transmission by the station on the transmission side is possible based on at least one of the signal level, the reception level of the control signal, and the number of hops from the station that is the starting point on the transmission side to the own station; And a notification means for notifying the transmitting side station of the desired signal level according to the result of the means.

That is, at the receiving station in packet transmission, when receiving a packet, the interference level measuring means measures the interference level, and the desired signal level calculating means calculates the desired signal based on the interference level obtained by the measurement. Calculate the level. Then, the determination means, based on at least one of the interference level, the desired signal level, the reception level of the control signal, and the number of hops from the station that is the starting point of the transmission side to the own station,
The transmitting unit determines whether or not packet transmission is possible, and the notifying unit notifies the transmitting station of the desired signal level according to the result of the determining unit. In this way, the interference level at the receiving station, the desired signal level, the control signal reception level,
Also, based on at least one of the number of hops from the station that is the origin of the transmitting side to the own station, the receiving station determines whether or not the transmitting station can transmit the packet, and the desired signal is determined according to the determination result. The level is notified to the transmitting station. As a result, the packet transmission of the station on the transmission side is performed based on at least one of the interference level at the station on the reception side, the desired signal level, the reception level of the control signal, and the number of hops from the station that is the origin of the transmission side to the own station. Appropriate acceptance / rejection decisions can be implemented at the receiving station.

In the wireless communication system as described above,
The station on the receiving side receives at least one of the reception level of the control signal, the interference level of the local station, and the number of hops from the station that is the starting point of the transmitting side to the local station, and then receives the next packet that is the destination of the packet. It is desirable to have a configuration further including a transmission destination determining unit that determines the station.

As the interference level measured by the interference level measuring means, the interference level at the local station of the channel group used for receiving the packet can be adopted.

The radio packet transmission method to which the present invention is applied is not particularly limited, but in particular, a method of specifying a user by a code using the same frequency and the same time (eg, CDMA). , OF
Suitable for CDM). In particular, the present invention preferably uses a CDMA system as a wireless packet transmission system, and an application example thereof will be described later.

Further, in order to achieve the above object, a radio communication system according to the present invention includes a base station, a mobile station, and a relay station having a relay function for packet transmission, and A wireless communication system using CDMA as a wireless multiplexing system, wherein the base station or the relay station, when receiving a packet, interference level measuring means for measuring an interference level at a local station of a channel group used for reception, Desired signal level calculation means for calculating a desired signal level based on the interference level obtained by measurement, and a desired signal level notification means for notifying the calculated desired signal level to the mobile station, the mobile station, Transmission power amount calculating means for calculating the transmission power amount of the packet based on the desired signal level notified from the base station or the relay station,
And a determination unit that determines whether or not the packet can be transmitted to the station that has notified the desired signal level, based on the transmission power amount calculated by the transmission power amount calculation unit.

That is, in the base station or the relay station, the desired signal level calculating means calculates the desired signal level based on the reception level of the packet transmitted from the mobile station and the interference level in the own station, and the desired signal level notifying means. Notifies the mobile station of the calculated desired signal level. Then, in the mobile station, the transmission power amount calculation means calculates the transmission power amount of the packet based on the notified desired signal level, and the determination means notifies the desired signal level based on the calculated transmission power amount. Determine whether to send a packet to the original station.
In this way, the mobile station controls the packet transmission by searching for the connection destination and judging whether or not the packet transmission is possible, based on the interference level at the base station or the relay station. In this way, the mobile station receives the notification of the desired signal level obtained based on the interference level of the partner station, calculates the transmission power amount of the packet based on the desired signal level, and calculates the calculated transmission power amount. Since it is determined whether or not the packet transmission to the station of the other party is possible based on the above, it is possible to realize the appropriate packet transmission availability determination according to the interference level of the station of the other party,
It is possible to avoid inconveniences such as a hidden terminal problem, an increase in traffic, and a decrease in system throughput regardless of the arrangement of relay stations.

The present invention is applicable not only to upstream packet transmission from a mobile station to a base station via a relay station, but also to downlink packet transmission from a base station to a mobile station via a relay station. A wireless communication system according to the present invention includes a base station, a mobile station, and a relay station having a relay function for packet transmission, and uses CDMA as a wireless multiplexing scheme for packet transmission. And each of the base station, the relay station and the mobile station,
When receiving a packet, interference level measuring means for measuring the interference level at the local station of the channel group used for reception, desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, Desired signal level notifying means for notifying the desired signal level to the station that is the source of the packet, and when transmitting or relaying the packet, the transmission power amount of the packet based on the desired signal level notified from another station. A transmission power amount calculating means for calculating the transmission power amount; and a determination means for determining, based on the transmission power amount calculated by the transmission power amount calculating means, whether or not it is possible to transmit a packet to the station that has notified the desired signal level. It is characterized by that.

As described above, the base station, the relay station and the mobile station are commonly provided with the interference level measuring means, the desired signal level calculating means, the desired signal level notifying means, the transmission power amount calculating means and the judging means, and In the packet transmission in the direction and the downlink, the base station, the relay station, and the mobile station perform the packet transmission control by searching the connection destination based on the interference level in the transmission partner and judging whether or not the packet transmission is possible.

For example, when performing packet transmission from the base station to one relay station in the downlink direction, in the one relay station, the desired signal level calculating means determines the reception level of the packet transmitted from the base station and its own station. The desired signal level is calculated based on the interference level in, and the desired signal level notifying unit notifies the base station of the calculated desired signal level. Then, in the base station, the transmission power amount calculating means calculates the transmission power amount of the packet based on the notified desired signal level, and the judging means notifies the desired signal level based on the calculated transmission power amount. Determine whether to send a packet to the original station. As a result, even in downlink communication, it is possible to realize appropriate packet transmission availability judgment according to the interference level of the partner station, and there is a hidden terminal problem, an increase in traffic, a decrease in system throughput, etc., regardless of the arrangement of relay stations. It is possible to avoid the inconvenience.

In the above-mentioned various wireless communication systems, each of the base station, mobile station, and relay station forming the wireless communication system,
It is desirable to have a configuration having the following means (functions).

That is, the base station belongs to mobile stations and relay stations that can directly communicate with the own station, and belonging information to mobile stations and relay stations that can directly communicate with the relay station without directly communicating with itself. It is desirable to further include a belonging information holding unit that holds and.

Further, the base station becomes a destination of the packet based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station which is the origin of the transmitting side to the own station. It is desirable to have a configuration further including a transmission destination determining unit that determines a mobile station or a relay station.

As the method of determining the destination by the destination determining means and the destination determining means described later, for example, a method of minimizing the number of hops (FIG. 7), a reception SIR of control signal and control There is a method (FIG. 8) of selecting a station having a minimum relative transmission power calculated from the interference level at the signal transmission source. These will be described later.

Further, the base station applies channel group selection means for selecting a transmission / reception channel group based on a packet transmission direction and a signal to be transmitted to a predetermined channel corresponding to the selected channel group. It is desirable to further include a signal transmitting means for transmitting.

Further, the mobile station further comprises a transmission destination determining means for determining a base station or a relay station to which the packet is transmitted, based on the reception level of the control signal or the number of hops from the base station to the own station. It is desirable to have a different configuration.

[0029] Further, the mobile station selects channel group selection means for selecting a transmission / reception channel group based on either or both of the number of hops from the base station to the own station or the packet transmission direction, and a signal to be transmitted, It is desirable to further include a signal transmitting unit for transmitting the signal on a predetermined channel according to the selected channel group.

Further, the relay station has a destination determining means for determining a station to which the packet is relayed, based on the reception level of the control signal or the number of hops from the station which is the origin of the transmission side to the own station. It is desirable to have a configuration further provided.

The relay station also decodes the signal received from the mobile station, the base station and another relay station by despreading it into an information series signal, and spreads the decoded information series signal. It is desirable to further include a spread signal generating means for generating a spread signal in.

When the relay station includes at least the transmission power amount calculating means, the transmission power calculated by the transmission power amount calculating means is assigned to the spread signal generated by the spread signal generating means, It is desirable that the spread signal is transmitted.

Further, the relay station selects channel group selection means for transmitting and receiving, based on either or both of the number of hops from the station which is the starting point on the transmission side to the own station and the packet transmission direction, and transmission. Signal to be
It is desirable to further include a signal transmitting unit for transmitting the signal on a predetermined channel according to the selected channel group.

The relay station in the present invention may be constituted by a station having the function of the mobile station, or a device installed in a vehicle or a stationary facility.

By the way, the present invention can be understood not only as an invention as a radio communication system but also as an invention of each of a base station, a mobile station, and a relay station constituting the system,
Has the same action and effect. That is, it can be described as follows.

A base station according to the present invention is a base station that constitutes a wireless communication system for performing communication based on a wireless packet transmission system together with a mobile station and a relay station having a relay function for packet transmission, and receives a packet. In this case, the interference level measuring means for measuring the interference level, the desired signal level calculating means for calculating the desired signal level based on the interference level obtained by the measurement, and the calculated desired signal level for the transmitting side of the packet. And a desired signal level notifying means for notifying the station.

As the interference level measured by the interference level measuring means, the interference level at the local station of the channel group used for receiving the packet can be adopted.

A base station according to the present invention is a base station which constitutes a wireless communication system using CDMA as a wireless multiplexing system for packet transmission, together with a mobile station and a relay station having a relay function for packet transmission. When receiving a packet, an interference level measuring means for measuring an interference level in a local station of a channel group used for reception, a desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, A desired signal level notifying unit for notifying the calculated desired signal level to the station on the transmission side of the packet.

A base station according to the present invention is a base station which constitutes a wireless communication system using CDMA as a wireless multiplexing system for packet transmission, together with a mobile station and a relay station having a relay function for packet transmission. When receiving a packet, an interference level measuring means for measuring an interference level in a local station of a channel group used for reception, a desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, Desired signal level notifying means for notifying the calculated desired signal level to the transmission source station of the packet, and when transmitting the packet, the transmission power amount of the packet is calculated based on the desired signal level notified from another station. And a notification source of the desired signal level based on the transmission power amount calculated by the transmission power amount calculation unit. Determination means for determining whether the packet transmission to the station, characterized by comprising a.

In this base station, the belonging information of the mobile station and the relay station which can directly communicate with the own station and the belonging information of the mobile station and the relay station which cannot directly communicate with the own station but can communicate directly with the relay station. It is desirable to have a configuration further including a belonging information holding unit that holds the belonging information.

Also, in this base station, the packet becomes the destination of the packet based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station which is the origin of the transmitting side to the own station. It is desirable to have a configuration further including a transmission destination determining unit that determines a mobile station or a relay station.

Also, in this base station, channel group selection means for selecting a transmission / reception channel group based on the packet transmission direction, and a signal to be transmitted are placed on a predetermined channel corresponding to the selected channel group. It is desirable to further include a signal transmitting means for transmitting.

A mobile station according to the present invention is a mobile station that constitutes a radio communication system for performing communication based on a radio packet transmission system together with a base station and a relay station having a relay function for packet transmission, and transmits a packet. Transmission power amount calculation means for calculating the transmission power amount of a packet based on the desired signal level notified from the transmission side station, and the transmission side station based on the transmission power amount calculated by the transmission power amount calculation means. And a determination means for determining whether or not a packet can be transmitted to the packet.

The mobile station, when receiving a packet, has an interference level measuring means for measuring an interference level, a desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, It is desirable to further include a desired signal level notifying unit for notifying the calculated desired signal level to the station on the transmission side of the packet.

At this time, as the interference level measured by the interference level measuring means, the interference level at the local station of the channel group used for receiving the packet can be adopted.

A mobile station according to the present invention is a mobile station that constitutes a radio communication system using CDMA as a radio multiplexing system for packet transmission, together with a base station and a relay station having a relay function for packet transmission. , Based on the transmission power amount calculation means for calculating the transmission power amount of the packet based on the desired signal level notified from the base station or the relay station, and the transmission power amount calculated by the transmission power amount calculation means, Determination means for determining whether or not the packet transmission to the station that has notified the desired signal level is possible.

The mobile station is a packet transmission destination based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station that is the origin of the transmission side to the own station. It is desirable that the configuration further includes a transmission destination determining unit that determines a base station or a relay station.

Also, in this mobile station, channel group selection means for selecting a transmission / reception channel group based on either or both of the number of hops from the base station to the own station and the packet transmission direction, and a signal to be transmitted are It is desirable to further include a signal transmitting means for transmitting the signal on a predetermined channel according to the selected channel group.

A relay station according to the present invention is a relay station that configures a wireless communication system for performing communication based on a wireless packet transmission system together with a base station and a mobile station and has a relay function for packet transmission. When receiving, the interference level measuring means for measuring the interference level, the desired signal level calculating means for calculating the desired signal level based on the interference level obtained by the measurement, and the calculated desired signal level, And a desired signal level notifying means for notifying the station on the transmitting side.

The relay station, based on at least one of the interference level, the desired signal level, the reception level of the control signal, and the number of hops from the station that is the origin of the transmission side to the own station, the relay station of the transmission side. It is preferable that the apparatus further comprises a judging means for judging whether or not the packet can be transmitted, and the desired signal level notifying means notifies the transmitting side station of the desired signal level according to the result of the judging means.

As the interference level measured by the interference level measuring means, the interference level at the local station of the channel group used for receiving the packet can be adopted.

Further, the relay station according to the present invention is a relay station having a relay function for packet transmission, which constitutes a radio communication system using CDMA for the radio multiplexing method for packet transmission, together with a base station and a mobile station. Then, when receiving the packet, an interference level measuring means for measuring the interference level at the local station of the channel group used for reception,
A desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, and a desired signal level notifying means for notifying the calculated desired signal level to the station on the transmitting side of the packet are provided. It is characterized by

Further, the relay station according to the present invention, when relaying a packet, the transmission power amount calculating means for calculating the transmission power amount of the packet based on the desired signal level notified from another station, and the transmission power. It is desirable that the configuration includes a determination unit that determines whether or not the packet can be transmitted to the station that has notified the desired signal level based on the transmission power amount calculated by the amount calculation unit.

In the relay station, based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station that is the origin of the transmission side to the own station, the packet relay destination is determined. It is desirable to have a configuration that further includes a transmission destination determining unit that determines a different station.

In the relay station, by decoding the signals received from the mobile station, the base station and other relay stations by despreading them into information series signals, and by spreading the decoded information series signals, It is desirable to further include a spread signal generation unit that generates a spread signal.

Further, in the relay station, when the relay station includes at least the transmission power amount calculation means, the transmission power calculated by the transmission power amount calculation means is added to the spread signal generated by the spread signal generation means. Is assigned,
It is desirable that the spread signal is transmitted.

In the relay station, channel group selecting means for selecting a transmission / reception channel group based on the number of hops from the station which is the origin of the transmission side to the own station, and a signal to be transmitted are the selected channel group. It is desirable to further include a signal transmitting means for transmitting the signal on a predetermined channel according to the above.

In the relay station, the relay station may be a station having the function of the mobile station, or a relay device installed in a vehicle or a stationary facility.

By the way, the present invention relates to the invention as a radio communication system and the base stations, mobile stations,
In addition to the inventions of the relay stations, the invention can be understood as an invention of a packet transmission control method executed in a wireless communication system, and the same action and effect are exhibited. That is, it can be described as follows.

A packet transmission control method according to the present invention comprises a base station, a mobile station, and a relay station having a relay function for packet transmission by multihop, and performs communication based on a wireless packet transmission system. A packet transmission control method in a wireless communication system, wherein a receiving side station in the packet transmission measures an interference level, and the receiving side station is based on the interference level obtained by the measurement. A desired signal level calculating step of calculating a desired signal level, a desired signal level notifying step in which the receiving station concerned notifies the transmitting side station of the calculated desired signal level, and the transmitting side station makes the notification The transmission power amount calculating step of calculating the transmission power amount of the packet based on the desired signal level, and the transmitting station, based on the calculated transmission power amount, The determination step of determining whether or not the packet can be transmitted to the receiving station, and the transmitting station determines the power of the transmission power amount for the receiving station with respect to the receiving station that is determined to be able to transmit the packet. And a packet transmitting step of transmitting a packet by using. It should be noted that in a certain aspect of packet transmission, all of the base station, mobile station, and relay station may be the “receiving side station”. Similarly, each of the base station, mobile station, and relay station may be the “transmitting station”.

Further, the packet transmission control method according to the present invention comprises a base station, a mobile station, and a relay station having a relay function for packet transmission, and CDMA is used as a wireless multiplexing system for packet transmission. In a wireless communication system to be used, a packet transmission control method executed when a packet is transmitted from a mobile station to a base station via a relay station, in which a station on a packet receiving side receives a packet in its own station. An interference level measuring step of measuring an interference level, a receiving side station, a desired signal level calculating step of calculating a desired signal level based on the interference level obtained by the measurement, and a receiving side station are calculated. And a desired signal level notifying step of notifying the desired signal level to the station on the transmitting side of the packet, and the station on the transmitting side transmits the packet based on the notified desired signal level. A transmission power amount calculating step for calculating the power, a determination step for the transmitting side station to determine whether or not packet transmission to the receiving side station is possible based on the calculated transmission power amount, and a transmitting side The station includes a packet transmitting step of performing packet transmission to a receiving station that is determined to be capable of packet transmission using the power of the transmission power amount of the receiving station.

Here, the mobile station which has become the receiving station has at least one of the reception level of the control signal, the interference level of its own station, and the number of hops from the station which is the starting point of the transmitting side to its own station. Based on the above, it is desirable to further include a mobile station transmission destination determining step of determining a base station or a relay station to which the packet is transmitted.

Further, in the above packet transmission control method, the base station which has become the receiving side station receives the control signal reception level,
A base station transmission destination determining step of determining a mobile station or a relay station to which a packet is transmitted based on at least one of the interference level of the own station and the number of hops from the station that is the origin of the transmission side to the own station It is desirable to have.

Further, in the above packet transmission control method, the relay station which has become the receiving station receives the control signal reception level,
A relay station transmission destination determining step of determining a transmission destination of the packet relay based on at least one of the interference level of the own station and the number of hops from the transmission source origin station to the own station Is desirable.

Further, the above packet transmission control method includes a decoding step in which the relay station despreads signals received from the mobile station, the base station and other relay stations to decode them into an information series signal, and the relay station. However, it is desirable to further include a spreading signal generation step of generating a spreading signal by spreading the decoded information sequence signal.

Further, in the above packet transmission control method, the mobile station and the relay station transmit and receive channels based on either or both of the number of hops from the station which is the origin of the transmission side to the own station and the packet transmission direction. A channel group selection step of selecting a group and selecting a transmission / reception channel group based on the transmission direction of packets by the base station, the mobile station, the relay station and the base station, a signal to be transmitted, It is desirable to further include a signal transmitting step of transmitting the signal on a predetermined channel according to the selected channel group.

Further, in the above packet transmission control method, it is desirable to divide the transmission channel into a plurality of channel groups and to allocate to the upstream signal and the downstream signal as follows.

For example, in the channel group selection step, the transmission channels for signal transmission are divided into two channel groups, and one channel group is commonly used by the base station, the relay station and the mobile station. It is desirable that the uplink signal that is the transmission source is assigned and the other channel group is assigned to the downlink signal that is the transmission source of the base station.

In the channel group selecting step, the transmission channels for signal transmission are divided into four channel groups, and the number of hops from the base station, the even-numbered relay stations from the base station, and the base station for the mobile station is set. , The first channel group is assigned to the downlink signal whose source is the base station, and the second channel group is the uplink source whose mobile station is the source. The third channel group is assigned to the downlink signal in common with the mobile station when the relay station is assigned to a signal and has an odd number from the base station and the mobile station has an odd number of hops from the base station. Desirably, a fourth channel group is assigned for the upstream signal.

In the channel group selecting step, the transmission channels for signal transmission are divided into N (N is an integer of 3 or more) channel groups, and each of the base station, the relay station and the mobile station has a single channel. The N channel groups are allocated such that the same channel group is allocated to the transmitted upstream signal and the downstream signal in the station, and different channel groups are allocated to the received upstream signal and the downstream signal. Is desirable.

Further, in the channel group selecting step, the transmission channels for signal transmission are divided into two channel groups, and the transmission from the base station, the even-numbered relay station from the base station and the mobile station is the first. It is preferable that the second channel group perform reception in the second channel group, the second channel group performs transmission from the base station and the odd-numbered relay stations and mobile stations, and the first channel group performs reception.

The channel group may be composed of channel groups divided by frequency,
The channel group may be divided by time, or the channel group may be divided by both frequency and time. These specific aspects will be described later.

As described above, according to the present invention, it is possible to solve the problem that the communication at the mobile station cannot be established due to the arrangement of the base stations, and at the same time, hide in the multi-hop method using the conventional CSMA or TDMA method. Problems such as occurrence of terminal problems, increase in traffic, and decrease in system throughput can be solved together. In addition, it is possible to reduce interference and improve frequency utilization efficiency by a unique channel group allocation method.

[0074]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

[Overview of Mobile Communication System] In the mobile communication system of the present embodiment, there are three stations that are involved in one communication: a "base station", a "relay station", and a "mobile station". Of these, the base station is a station that can be connected to another base station via the core network, and the mobile station is a terminal that first requests packet transmission or receives the packet last. The relay station is a terminal (relay terminal) that functions to relay a packet from the mobile station to the base station or to relay a packet from the base station to the mobile station.
Since power is consumed by packet relaying, it is thought that in addition to terminals that operate with conventional batteries, it is possible to receive power supply by solar cells, generators, or wires, so that telecommunications carriers can provide area coverage. There may be things that aim to reduce costs instead of base stations, those that receive electricity while moving like cars and trains, and those that are fixedly supplied with power such as vending machines. . That is, the relay station corresponds to one having both the function of a mobile station and the relay function, as well as a relay device installed in a vehicle such as an automobile or a train and a vending machine.

In the following, focusing on one aspect of communication in a mobile communication system, a mobile station that is a packet transmission source or a packet transmission destination in the communication is referred to as a “mobile station”, and a terminal or a relay device that can function as a relay station will be described. This will be described as a "relay station".

By the way, in this system, the base station is
It is necessary to secure the connection with the mobile station either directly or via one or more relay stations. For this reason, each base station has not only the belonging information of the mobile station that can communicate directly, but also the belonging information of the relay station that can communicate directly and the affiliation of the mobile station that cannot connect directly but that can be connected via the relay station. By updating and holding the information at predetermined time intervals, the belonging information of all mobile stations that can communicate directly and indirectly can be held, and the direct and indirect communication with the base station is possible. Connections with all mobile stations are secured.

Each mobile station and relay station transmits a request signal having the ID of its own station as information for securing a connection route to the base station at a predetermined time interval (or when a transmission packet occurs). All the stations that have received the request signal include relay information (for example, the ID of the local station, the ID of the mobile station that transmitted the request signal, the interference level at the local station) in the control signal indicating that the mobile station can be connected to the mobile station. , Including information such as the number of hops to the base station). The mobile station that has received the control signal determines a connection route from the information of the signal, transmits an ACK signal to the station to be connected, and determines the connection route.

For example, the mobile station 21 shown in FIG. 2 transmits a request signal to secure a connection route to the base station 24. The dotted line circle represents the reach of the request signal from the mobile station 21, and the relay station 2 existing within the reach.
When receiving the request signal, the reference numerals 2 and 23 transmit the control signal to which the relay information is added. Then, when the mobile station 21 receives this control signal, the mobile station 21 determines a connection route from the relay information of the control signal, and transmits an ACK signal to the station (for example, the relay station 22) to be connected,
The connection path (mobile station 21-relay station 22-base station 24) is established.

The configurations of the relay station, mobile station, and base station that form the present system will be described below, focusing on the points related to the present invention.

[Relay Station] In the present embodiment,
The relay station does not function as a repeater that relays the received signal as it is, but has the function of demodulating and decoding the signal received from another mobile station or base station and converting it into an information sequence. Is a terminal that calculates the transmission power according to the desired signal level notified from the station (packet transmission destination) that should receive, and encodes and modulates the information sequence again, puts it on the desired channel, and transmits. When CDMA is used as the access method, the relay station further has a function of despreading the received signal and a function of spreading the obtained information sequence again.

Here, by having the function of calculating the transmission power according to the desired signal level of the packet transmission destination, stable and highly reliable transmission using the transmission power is realized. Further, the gain of the signal can be corrected by once decoding the received signal into the information sequence at the relay station.

Here, the configuration of the relay station will be described with reference to FIG. 17, taking the case where the access method is CDMA as an example. As shown in FIG. 17A, the relay station 30 includes a control signal processing unit 31 that processes a signal for securing a line to the base station and a data processing unit 32 that processes packet data. And the number of packets that can be relayed in parallel (this corresponds to the number of packets that can be relayed simultaneously,
In the example of FIG. 17A, the number of data processing units 3 is “3”).
Equipped with 2.

The data processing unit 32 extracts a desired signal from the received signal and reproduces it as an information sequence. The reproduced information sequence is encoded and D / A converted again, and converted into the transmission power amount calculated from the information (for example, the interference level and the propagation loss information of the packet transmission destination) obtained from the transmission power control unit (not shown). It is transmitted on the carrier wave amplified accordingly. In addition,
The transmission power control unit may be installed in the control signal processing unit 31, or may be installed in the relay station 30 independently of the control signal processing unit 31.

The control signal processor 31 is shown in FIG.
As shown in (b), an interference level measuring unit 31A that measures an interference level in the local station, a demodulator / channel decoder 31B that demodulates and decodes an input signal, and a relay station that selects a relay station. A selector 31C, a hop information buffer 31E for storing hop information, an ACK signal generator 31F for generating an ACK signal, a control signal generator 31G for generating a control signal, and a request for generating a request signal. And a signal generator 31H.

The control signal processing section 31 determines the route for connecting the base station and the mobile station (which relay station is used). As shown in FIG. 17B, the request signal, the control signal, and the ACK signal input to the control signal processing unit 31 are distinguished by the demodulator / channel decoder 31B for each signal type and each transmission source station. , Request signal is control signal generator 31
It is input as a G trigger, the control signal is input to the relay station selector 31C, the ACK signal is input to the hop information buffer 31E, and the higher order (close to the base station).
The information is passed to the station.

The relay station selector 31C receives a control signal transmitted from a nearby station, and receives power to interference signal power ratio (Signal to Inte
rference Ratio: hereinafter referred to as “SIR”), based on information such as the interference level at the control signal source and the number of hops to the base station, the relay station or base station to be connected next (hereinafter “connecting station”) Say).

Next, the configuration of the relay station when the channel group used for relay is selected for each relay by the channel group allocation method described later will be described with reference to FIG.

In the data processing section 32 shown in FIG. 3 (a),
A desired signal is extracted from the received signal based on the information obtained from the channel group selector 31D of FIG.
Information is reproduced by despreading. The reproduced information sequence is again encoded, spread, D / A converted, and calculated from information obtained from the transmission power control unit (not shown) (for example, information on the interference level and propagation loss of the packet transmission destination). The signal is transmitted by being carried on a carrier wave (a carrier wave determined by the channel group selector 31D) amplified according to the amount of transmission power.
In addition, the transmission power control unit includes the control signal processing unit 31.
It may be installed in the relay station 30, or may be installed in the relay station 30 independently of the control signal processing unit 31.

The control signal processor 31 is shown in FIG.
As shown in (b), when receiving a packet, an interference level measuring unit 31A that measures the interference level in the local station of the channel group used for the reception, and a demodulator / channel that demodulates / decodes the input signal Decoder 31B, relay station selector 31C for selecting a relay station, channel group selector 31D for selecting a channel group, hop information buffer 31E for storing information such as the number of hops, and ACK signal ACK signal generator 31 for generating
F, a control signal generator 31G for generating a control signal, and a request signal generator 31H for generating a request signal.

The control signal processing unit 31 determines the route for connecting the base station and the mobile station (which relay station is used). As shown in FIG. 3 (b),
The request signal, the control signal, and the ACK signal input to the control signal processing unit 31 are distinguished by the demodulator / channel decoder 31B for each signal type and transmission source station, and the request signal is controlled by the control signal generator 31G. The control signal is input as a trigger, the control signal is input to the relay station selector 31C, the ACK signal is input to the hop information buffer 31E, and the information is passed to a higher-order station (close to the base station).

The relay station selector 31C receives a control signal transmitted from a nearby station, receives the control signal from the received power to interference signal power ratio (SIR),
The connection group (relay station or base station) to be connected next is determined based on information such as the interference level at the control signal source and the number of hops to the base station, and the channel group selector 31D determines the number of hops to the base station. The transmission / reception channel group is determined according to

[About Mobile Station] Next, the configuration of the mobile station will be described with reference to FIGS. 4A and 18. As shown in FIG. 4A, the mobile station 40 processes input data, transmits a processed data, and a transmission data processing unit 41, processes a received signal, and converts the processed data into output data. And a control signal processing unit 4 for processing a control signal, a request signal, and an ACK signal.
2 is included.

As shown in FIG. 18, the control signal processing section 42 includes a demodulator / channel decoder 42B for demodulating / decoding an input signal, a relay station selector 42C for selecting a relay station, A hop information buffer 42E for storing hop information and the like, and A for generating an ACK signal
It is configured to include a CK signal generator 42F and a request signal generator 42G that generates a request signal.

In addition, it is desirable to have a structure including an interference level measuring unit 42A for measuring the interference level at the own station, which is shown by a broken line in FIG. 18, and is directed from the base station to the mobile station via the relay station. In all downlink packet transmissions, it is possible to determine whether or not the relay station can transmit packets based on the interference level at the mobile station, similarly to the uplink packet transmissions. In the present embodiment, it is assumed that the interference level measuring unit 42A indicated by the broken line in FIG. 18 also exists, and the packet transmission control according to the present invention is performed by packet transmission in both the up and down directions. A method of determining a connection route relating to this control will be described later.

In the control signal processing section 42 of the mobile station 40, the demodulator / channel decoder 42B
The control signal determined for each transmitting station is input to the relay station selector 42C. And the relay station selector 4
2C selects one relay station or base station that meets the connection conditions, and the ACK signal generator 42F transmits an ACK signal to the selected connection station. At the same time,
Writing to the hop information buffer 42E is performed.

Next, the configuration of the mobile station when the channel group used for relay is selected for each relay by the channel group allocation method described later will be described with reference to FIG. 4 (b). Note that the schematic configuration of the mobile station 40 shown in FIG. 4A is the same as the configuration described above, and therefore description thereof will be omitted. However, the configuration of the control signal processing unit 42 is different from the configuration described above, and will be described below.

The control signal processor 42 is shown in FIG.
As shown in (b), a demodulator / channel decoder 42B that demodulates / decodes an input signal, a relay station selector 42C that selects a relay station, and a channel group selector that selects a channel group. 42D, a hop information buffer 42E for storing information such as the number of hops, and AC
It is configured to include an ACK signal generator 42F that generates a K signal and a request signal generator 42G that generates a request signal.

In addition to this, a configuration including an interference level measuring unit 42A for measuring the interference level at the local station of the channel group used for receiving the packet, which is shown by the broken line in FIG. It is desirable to determine whether to allow packet transmission of the relay station based on the interference level at the mobile station in the packet transmission in the downlink direction from the base station to the mobile station via the relay station, in the same manner as the packet transmission in the uplink direction. It becomes feasible. In the present embodiment, it is assumed that the broken line interference level measuring unit 42A is also present, and the packet transmission control according to the present invention is performed in both upstream and downstream packet transmission. A method of determining a connection route relating to this control will be described later. The channel used for packet transmission may be a predetermined channel or may be determined for each relay. Also, the channels may be grouped.

In the control signal processing section 42 of the mobile station 40, the demodulator / channel decoder 42B
The control signal determined for each transmitting station is input to the relay station selector 42C. And the relay station selector 4
2C selects one relay station or base station (that is, connection station) that meets the connection conditions, and an ACK signal generator 42F transmits an ACK signal to the selected connection station, and at the same time, a hop information buffer 42E. Writing to F and selecting a channel group used for transmission / reception by the channel group selector 42D.

[Base Station] Next, the configuration of the base station will be described with reference to FIG. As shown in FIG. 5A, the base station 50 processes the transmission data from the core network and transmits the processed data, and a transmission signal processing unit 51,
A reception signal processing unit 53 that processes a reception signal and generates reception data to be sent to the core network, and a control signal processing unit 52 that processes a request signal, a control signal, and an ACK signal are configured.

Of these, the control signal processing unit 52
As shown in FIG. 5B, an interference level measuring unit 52A that measures the interference level at the local station, a demodulator / channel decoder 52B that demodulates / decodes the input signal, and information such as the number of hops are displayed. Hop information buffer 5 for storing
2C and a control signal generator 52D that generates a control signal.

In the control signal processing section 52 of the base station 50, the received signal is first demodulated and decoded by the demodulator / channel decoder 52B, and the request signal and the ACK signal are discriminated for each transmitting station. The request signal functions as a trigger for operating the control signal generator 52D. When the ACK signal is received, the hop information of the signal transmission source is written in the hop information buffer 52C.

[Method of Determining Connection Path in Each of Mobile Station, Relay Station, and Base Station] By the way, whether communication between each station is possible depends on whether the station on the packet receiving side of the channel used for communication between the corresponding stations receives the packet. Determined by SIR. That is, the received SI at the station that receives the packet
When R exceeds the required value, it is determined that communication is possible, and when the received SIR is less than the required value, it is determined that communication is impossible. This decision may be made by the receiving station based on the interference level at its own station, or by the receiving station notifying the transmitting station of the interference level so that the sending station performs it. You can also

There may be a plurality of stations determined to be communicable in this way. In this case, a method for determining the connection route to the base station will be described in detail below. As a method of determining the connection path, a method of minimizing the number of hops (that is, the number of hops from the base station to the own station) (FIG. 7), a reception SIR of the control signal, and an interference level at the control signal transmission source are used. There is a method (FIG. 8) of selecting a station having the smallest calculated relative transmission power.
Hereinafter, these methods will be described by taking as an example the case where the mobile station is mainly used.

In the method of minimizing the number of hops (FIG. 7), the mobile station selects the relay station or the base station that has transmitted the control signal, which has the smallest number of hops. However, the number of hops of the base station is set to 0, and when the number of hops is the same, the station having the maximum SIR is selected from those stations.

Specifically, the processing of FIG. 7 is executed in the mobile station. First, the control signal s from a nearby relay station or base station is detected and decoded (S00).
1). Counter i is initialized to 0 (S002)
After that, a set S of control signals s for which the number of hops (Nhop) = i is extracted (S003). Here, it is determined whether the set S is null (S004),
If the set S is empty, it is determined whether the counter i has reached the maximum number of hops defined by the system (S0
05). If the counter i has not reached the maximum number of hops, the counter i is incremented by 1 (S00
6), the process after S003 is re-executed for i after counting up.

If the set S of the control signals s for which the hop count = i is not empty in S004, the relative transmission power is calculated for all the elements of the set S (S00).
7). A station corresponding to the minimum relative transmission power among the calculated relative transmission powers is selected (S008). Further, the value obtained by adding 1 to the hop number i of the selected station is substituted for the hop number Nhop (S009), and the process is ended.

As a result, the mobile station can select the relay station or base station that has transmitted the control signal, which has the smallest number of hops. Moreover, when there are a plurality of stations having the smallest number of hops, the station having the maximum SIR can be selected from those stations.

If the counter i reaches the maximum number of hops in S005 before the set S of control signals s for which the number of hops = i is not empty is detected in S004, a station that can be a relay station is Since it can be determined that there is no hop, a negative number (for example, "-1") is assigned to the hop count Nhop as a hop failure (S010), and the process is terminated.

On the other hand, in the method of selecting the station having the smallest relative transmission power amount (FIG. 8), the transmission power of each received control signal is obtained, and the transmission power is calculated in ascending order of transmission power. It is sorted, and it is checked whether or not the number of hops is within a predetermined value in the sorted order. If it is within a predetermined value, the station is selected as a connecting station.

As a method of calculating the transmission power amount Ptx, for example, the interference level I (dBm) of the packet receiving station is used.
And the received signal level S (dB) of the control signal are used to represent the following equation (1).

Ptx = IS + constant term (1)

Specifically, the processing of FIG. 8 is executed in the mobile station. First, a control signal s from a nearby relay station or base station is detected and decoded (S10).
1). Then, relative transmission powers are calculated for all the control signals s (S102), and the control signals s are sorted so that the calculated relative transmission powers are in ascending order (S103).

The counter i is initialized to 1 (S10
4) After that, the i-th control signal s (i) is empty (nu
11) is determined (S105), and if the control signal s (i) is present, it is determined whether the hop count of the control signal s (i) is less than or equal to a predetermined value. (S106). When the number of hops of the control signal s (i) is larger than the predetermined value, the counter i is incremented by 1 (S107), and the counter i is incremented.
For S., the processing after S105 is re-executed.

If the hop count of the control signal s (i) is less than or equal to the predetermined value in S106, the control signal s (i)
The station that has transmitted (i) can determine that it is the station that has the smallest relative transmission power amount under the condition that the number of hops is equal to or less than the predetermined value, so the control signal s (i)
The station that has transmitted is selected (S108). Then, the value obtained by adding 1 to the hop count Nhop (i) of the selected station is substituted for the hop count Nhop (S109), and the process is terminated.

As a result, the mobile station can select the station having the minimum relative transmission power amount under the condition that the number of hops is equal to or less than the predetermined value. If it is determined in S105 that the control signal s (i) is empty, it can be determined that there is no station that can serve as a relay station, so it is determined as a hop failure and a negative number (for example, "-
1 ”) is substituted (S110), and the process ends.

Uplink packets generated in the mobile station and transmitted to the base station or downlink packets that reach the base station from the core network and are transmitted to the mobile station are connected by the connection determined by the above method. Packet communication is performed through the route.

As a method for determining the packet transmission power at this time, a training signal for determining a desired signal level is transmitted before packet transmission, and the desired signal determined from the reception level of the training signal and the interference level of the receiving station. A method of notifying the packet level of the signal level can be considered.

[Channel group allocation method]
The channel group allocation method, which is one of the features of the present invention, will be described in detail. The following four types of channel group allocation methods are available, for example. That is,
A first method using two channel groups, a second method using four channel groups, N (N is 3
A third method using channel groups of
It is four of the fourth methods using two channel groups. Hereinafter, they will be described in order.

In the first method, transmission channels for signal transmission are divided into two channel groups G1 and G2. As the method, it may be divided into two according to the frequency band as shown in FIG. 10A, or may be divided into two according to time as shown in FIG. 10B. FIG. 9 shows a concept of channel group allocation according to the first method, which includes a base station (BS), relay stations (HS1, HS2,
In the HS3) and the mobile station (MS), the channel group G1 is assigned to the downlink signal and the channel group G2 is assigned to the uplink signal in common.

Here, when the relay station relays continuous packets, the same channel is used for transmission and reception, so that the signal transmitted by the local station interferes with the received signal at the local station. The near-far problem may occur, but the interference canceller 35 shown in FIG.
6B is built in the relay station 30 so that both the reception signal and the transmission signal are input. The interference canceller 35 includes a 180-degree phaser 35A that shifts the phase of the input signal by 180 degrees, and an amplitude adjuster 35B that adjusts the attenuation of the transmission signal until the transmission signal reaches the receiving antenna 33.
And a built-in transmission signal from the transmission antenna 34
The 0-degree phase shifter 35A and the amplitude adjuster 35B convert the interference signal (transmission signal received by the reception antenna 33) into a signal that cancels the interference signal. By adding the signal that cancels this interference signal and the received signal (a signal that also includes the interference signal), the interference signal component included in the received signal is canceled, and a signal with interference removed is obtained.

In the first method, the allocation width of the frequency band shown in FIG. 10A or the allocation width of time shown in FIG. 10B can be appropriately set in the channel groups G1 and G2. Therefore, for example, when the information amount of the downlink signal is considerably larger than the information amount of the uplink signal, the allocation width of the downlink signal channel group G1 can be set to be considerably wider than the allocation width of the uplink signal channel group G2. It is possible to improve the efficiency of frequency use or the efficiency of time use. Also, by setting the number of divisions to a minimum of 2, it is possible to suppress so-called division loss.

In the second method, the transmission channel is divided into four channel groups G1, G2, G3 and G4.
As the method, as shown in FIG. 12A, the frequency band may be divided into four, or as shown in FIG. 12B, the time may be divided into four.
As shown in (c), 4 depending on the combination of frequency band and time.
You may divide into two. FIG. 11 shows the concept of channel group allocation according to the second method.
S), an even-numbered relay station (HS2) from the base station, and a mobile station (MS) having an even number of hops from the base station, the channel group G1 is a downstream signal and the channel group G2 is an upstream signal. Assigned to. Also,
The channel group G3 is commonly assigned to the downstream signal and the channel group G4 is commonly assigned to the upstream signal in the odd-numbered relay stations (HS1, HS3) from the base station.

In the second method, different from the first method, each relay station uses different channels for transmission and reception, so that the signal transmitted by the own station becomes the received signal at the own station. There is an advantage that there is little risk of causing so-called near-far problems that interfere. Therefore, it is not necessary to provide the interference canceller 35 shown in FIG. 6A in the relay station.

Also, with this second method, as shown in FIG.
It is possible to appropriately set the allocation width of each channel group of (c) to (c). Therefore, for example, when the information amount of the downlink signal is considerably larger than the information amount of the uplink signal, the allocation width of the downlink signal channel groups G1 and G3 is considerably wider than the allocation width of the uplink signal channel groups G2 and G4. By setting, it is possible to improve the frequency utilization efficiency or the time utilization efficiency.

In the third method, N transmission channels (N
Is an integer greater than or equal to 3), and the same channel group is assigned to the transmitted uplink signal and downlink signal in each of the base station, relay station, and mobile station, and the received uplink signal and downlink signal are assigned. Different channel groups are assigned depending on the signal. Here, the case of N = 3 will be described.

The transmission channel is divided into three channel groups G
As a method of dividing into 1, G2, and G3, as shown in FIG. 14A, it may be divided into three according to the frequency band,
As shown in FIG. 14 (b), it may be divided into three by time, or as shown in FIG. 14 (c), the channel group G2 is uniformly set for the predetermined time zone regardless of the frequency and other than the predetermined time zone. With regard to, the channel group G1 may have a frequency lower than the predetermined frequency, and the channel group G3 may have a frequency higher than the predetermined frequency. Further, as shown in FIG. 14D, the channel group G2 is uniformly applied to the predetermined frequency band regardless of time.
Except the predetermined frequency band, the predetermined time band is the channel group G1, and the other time bands are the channel group G.
It may be 3.

FIG. 13 shows the concept of channel group allocation according to the third method, in which data is transmitted to the base station (BS) and the Nth (third) relay station (HS3) from the base station. The same channel group 1 is assigned to the upstream signal and the downstream signal, and the first relay station (H
S1) and the mobile station (MS) located fourth from the base station
Is assigned the same channel group 2 for the uplink and downlink signals transmitted, and the second relay station (HS2) from the base station is assigned the same channel group for the uplink and downlink signals transmitted. 3 is assigned. As a result, different channel groups are allocated to the received uplink signal and downlink signal in the base station, mobile station, and each relay station. For example, relay station (HS1)
For channel group 2 for uplink and downlink transmission signals
However, the channel group 3 is assigned to the uplink received signal and the channel group 1 is assigned to the downlink received signal, so that it is possible to prevent interference between the signals.

In the fourth method, the transmission channel is divided into two channel groups G1 and G2. The division method may be the frequency division shown in FIG. 10A or the time division shown in FIG. 10B. FIG. 15 shows the concept of channel group allocation according to the fourth method, in which transmission from the base station and even-numbered relay stations and mobile stations from the base station is performed in the first channel group.
Reception is performed in the second channel group, transmission from the base station in odd-numbered relay stations and mobile stations is performed in the second channel group, and reception is performed in the first channel group. For example, in FIG. 15, the base station (BS), the second relay station HS2 from the base station, and the fourth mobile station (MS) from the base station.
The channel group G1 is assigned to the transmission signal and the channel group G2 is assigned to the reception signal. In addition, the channel group G2 is added to the transmission signals of the first relay station HS1 from the base station and the third relay station HS3 from the base station.
And the channel group G1 is assigned to the received signal.

By this means, transmission and reception in a certain relay station can be configured to be performed in different channel groups, so that mutual interference between transmitted and received signals can be prevented and the division loss can be prevented because of the minimum number of divisions. Can be suppressed.

By the peculiar channel group allocation method as described above, it is possible to reduce interference and improve frequency utilization efficiency.

The station on the receiving side estimates from the interference level instead of notifying the station on the transmitting side of the desired signal level in order to secure the receiving level of the signal received by itself, as in the above embodiment. The transmission level of the transmitting station may be notified.

By the way, there is an ad hoc wireless network as a technology expected in the next-generation mobile communication. It is intended to construct a flexible wireless information network by the terminal itself having a relay function and a multi-hop function without taking the communication form via the current fixed base station.

In order to support such an ad hoc wireless network, the base station may be provided with the function of a relay station so that the base station can perform an operation of relaying communication to another base station.

For example, as shown in FIG. 16, FIG.
The number of packets that can be relayed in parallel (this corresponds to the number of CDMA multi-codes, which is “3” in the example of FIG. 16) is added to the base station configuration of FIG. The processing unit 52 may be configured as a processing unit that processes a signal for securing a line to another base station. Here, the additional data processing unit 54 has the same configuration as the data processing unit 32 (FIG. 3A) of the relay station described above, and the control signal processing unit 52 controls the control signal processing unit 31 (FIG. 3 (a) and 3 (b)).

By thus providing the base station with the function of a relay station as well, it is possible to flexibly support an ad hoc wireless network.

Further, the radio communication system according to the present invention is
Via a local area network such as a wireless LAN such as a control station and a slave station, a packet communication network typified by hierarchical mobile IPv6, a small radio such as a radio tag, or a white goods that can be connected to the network. It goes without saying that it is applicable even in a pervasive network for communication. In that case, what is called a wireless control station, an access point, or a white goods household appliance is used as a base station of the present embodiment as a wireless station, a mobile node (mobile node), and a small wireless device (for example, a wireless tag). What is called corresponds to the mobile station of this embodiment.

Further, any of the radio control station, radio station, access point, mobile node, small radio, radio tag and white goods can be the mobile station, relay station or base station according to the present embodiment. Needless to say.

The area called cellular in this embodiment is
It goes without saying that each transmitting station in the network described above may be an area where radio waves can be emitted. In that case, the communication method is not limited to CDMA, and other wireless transmission methods may be used, such as infrared communication such as IrDA and Bluetooth, short-range communication such as non-contact magnetic reading, and myoelectricity between human bodies (generated from muscles). It goes without saying that contact type communication for reading and communicating weak electricity) may be used.

[0141]

As described above, according to the present invention, the multi-hop method using the conventional CSMA or TDMA method is solved while solving the problem that the communication at the mobile station cannot be established due to the arrangement of the base stations. Occurrence of hidden terminal problem of
Problems such as increased traffic and reduced system throughput can also be solved. In addition, it is possible to reduce interference and improve frequency utilization efficiency by a unique channel group allocation method.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a multi-hop cellular mobile communication system.

FIG. 2 is a conceptual diagram of a relay station search by a mobile station.

FIG. 3A is an overall configuration diagram of a relay station when a channel group is selected for each relay by a channel group allocation method, and FIG. 3B is a case where a channel group is selected for each relay by a channel group allocation method. 3 is a configuration diagram of a control signal processing unit in the relay station of FIG.

4A is an overall configuration diagram of a mobile station, and FIG. 4B is a configuration diagram of a control signal processing unit in the mobile station when a channel group is selected for each relay by a channel group allocation method.

5A is an overall configuration diagram of a base station, and FIG. 5B is a configuration diagram of a control signal processing unit in the base station.

FIG. 6A is a block diagram of an interference canceller,
(B) is a block diagram of a relay station provided with an interference canceller.

FIG. 7 is a flowchart of a relay station selection process that minimizes the number of hops.

FIG. 8 is a flowchart of a relay station selection process that maximizes the SIR of a control signal.

FIG. 9 is a conceptual diagram of a first channel group allocation method.

FIG. 10A is a diagram showing an example of setting two channel groups by frequency division, and FIG. 10B is a diagram showing an example of setting two channel groups by time division.

FIG. 11 is a conceptual diagram of a second channel group allocation method.

12A is a diagram showing an example of setting four channel groups by frequency division, FIG. 12B is a diagram showing an example of setting four channel groups by time division, and FIG. It is a figure which shows the example which sets four channel groups by both frequency division and time division.

FIG. 13 is a conceptual diagram of a third channel group allocation method.

14A is a diagram showing an example of setting three channel groups by frequency division, FIG. 14B is a diagram showing an example of setting three channel groups by time division, and FIG. It is a figure which shows the 1st example which sets three channel groups by both frequency division and time division,
(D) is a diagram showing a second example in which three channel groups are set by both frequency division and time division.

FIG. 15 is a conceptual diagram of a fourth channel group allocation method.

FIG. 16 is a configuration diagram of a base station having a function of a relay station.

17A is an overall configuration diagram of a relay station when a channel group is not selected, and FIG. 17B is a configuration diagram of a control signal processing unit in the relay station when a channel group is not selected. is there.

[Fig. 18] Fig. 18 is a configuration diagram of a control signal processing unit in the mobile station when a channel group is not selected.

[Explanation of symbols]

11, 13, 14, 21, 40 ... Mobile station, 12, 24,
50 ... Base station, 15 ... Obstacle, 22, 30 ... Relay station, 3
1 ... Control signal processing unit, 31A ... Interference level measuring unit, 31B ... Channel decoder, 31C ... Relay station selector,
31D ... Channel group selector, 31E ... Hop information buffer, 31F ... ACK signal generator, 31G ... Control signal generator, 31H ... Request signal generator,
32 ... Data processing unit, 33 ... Reception antenna, 34 ... Transmission antenna, 35 ... Interference canceller, 35A ... 180 degree phase shifter, 35B ... Amplitude adjuster, 41 ... Transmission data processing unit,
42 ... Control signal processing unit, 42A ... Interference level measuring unit, 42B ... Channel decoder, 42C ... Relay station selector, 42D ... Channel group selector, 42E ... Hop information buffer, 42F ... ACK signal generator, 42G ...
Request signal generator, 43 ... Received data processing unit, 51
... transmission signal processing unit, 52 ... control signal processing unit, 5
2A ... Interference level measuring unit, 52B ... Channel decoder, 5
2C ... Hop information buffer, 52D ... Control signal generator, 53 ... Received signal processing unit, 54 ... Data processing unit, G1, G2, G3, G4 ... Channel group, Nh
op ... hop number, Ptx ... transmission power amount, s ... control signal.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Yoshino             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo (72) Inventor Tohru Otsu             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo (72) Inventor Yasushi Yamao             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo F term (reference) 5K022 EE02 EE14 EE21 EE31                 5K035 AA02 CC08 CC10 DD01 EE04                       MM03 MM06                 5K067 AA21 BB04 BB21 DD11 DD51                       EE02 EE03 EE06 EE10 EE16                       FF02 GG08 HH22

Claims (53)

[Claims] 1. A wireless communication system configured to include a base station, a mobile station, and a relay station having a relay function for packet transmission by multi-hop, and performing communication based on a wireless packet transmission method, wherein: The receiving station in packet transmission, when receiving a packet, interference level measuring means for measuring an interference level, desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, And a desired signal level notifying unit for notifying the desired signal level to the station on the transmitting side, wherein the station on the transmitting side determines the transmission power amount of the packet based on the desired signal level notified from the station on the receiving side. Based on the transmission power amount calculating means for calculating and the transmission power amount calculated by the transmission power amount calculating means, it is determined whether or not the packet transmission to the receiving side station is possible. Wireless communication system comprising: the determining means. 2. A wireless communication system configured to include a base station, a mobile station, and a relay station having a relay function for packet transmission by multi-hop, and performing communication based on a wireless packet transmission method, wherein: The receiving station in packet transmission, when receiving a packet, interference level measuring means for measuring an interference level, desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, Judgment as to whether or not packet transmission by the transmitting station is possible, based on at least one of the interference level, the desired signal level, the control signal reception level, and the number of hops from the transmitting station to the own station. And a notifying unit for notifying the transmitting side station of the desired signal level according to the result of the judging unit. . 3. The station on the receiving side transmits a packet based on at least one of a reception level of a control signal, an interference level of the own station, and a hop number from a station as a starting point of the transmitting side to the own station. The wireless communication system according to claim 1, further comprising a transmission destination determining unit that determines a next receiving station to be a destination. 4. The interference level measured by the interference level measuring means is an interference level at a local station of a channel group used for receiving a packet, according to claim 1. Wireless communication system. 5. A wireless communication system including a base station, a mobile station, and a relay station having a relay function for packet transmission, wherein CDMA is used as a wireless multiplexing scheme for packet transmission, wherein the base When receiving a packet, the station or the relay station measures the interference level in the local station of the channel group used for receiving, and the desired signal level based on the interference level obtained by the measurement. A signal level calculation means, and a desired signal level notification means for notifying the calculated desired signal level to the mobile station, wherein the mobile station is based on the desired signal level notified from the base station or the relay station. A transmission power amount calculating means for calculating the transmission power amount of the packet, and the desired signal level based on the transmission power amount calculated by the transmission power amount calculating means. Wireless communication system comprising: the determination means, the determining whether the packet transmission to the notification source station. 6. A wireless communication system comprising a base station, a mobile station, and a relay station having a relay function for packet transmission, wherein CDMA is used as a wireless multiplexing system for packet transmission. When receiving a packet, each of the station, the relay station, and the mobile station measures the interference level in the local station of the channel group used for reception, and the desired level based on the interference level obtained by the measurement. Desired signal level calculating means for calculating the signal level, desired signal level notifying means for notifying the calculated desired signal level to the station that is the source of the packet, and when transmitting or relaying the packet, it is notified by another station. And a transmission power amount calculating means for calculating the transmission power amount of the packet based on the desired signal level, and a transmission power amount calculated by the transmission power amount calculating means. Then, a wireless communication system comprising: a determining unit that determines whether or not the packet can be transmitted to the station that has notified the desired signal level. 7. The belonging information of a mobile station and a relay station, wherein the base station can directly communicate with the own station,
7. The wireless communication according to claim 5, further comprising: affiliation information holding means that holds affiliation information of a mobile station and a relay station that are not directly communicable with the own station but can be directly communicated with the relay station. system. 8. The base station is a packet transmission destination based on at least one of a control signal reception level, an interference level of the own station, and a hop number from a station that is a starting point of a transmission side to the own station. 7. The wireless communication system according to claim 6, further comprising a destination determining unit that determines a mobile station or a relay station. 9. The base station selects channel group selection means for selecting a transmission / reception channel group based on a packet transmission direction, and a signal to be transmitted is placed on a predetermined channel corresponding to the selected channel group. 7. The wireless communication system according to claim 5, further comprising: a signal transmitting unit that transmits the signal. 10. The mobile station further comprises transmission destination determining means for determining a base station or a relay station to which a packet is transmitted, based on a reception level of a control signal or the number of hops from the base station to its own station. The wireless communication system according to claim 5, wherein 11. A channel group selection means for selecting a transmission / reception channel group based on the number of hops from the base station to the own station or both or one of the packet transmission directions, and a signal to be transmitted by the mobile station, 7. The wireless communication system according to claim 5, further comprising: a signal transmitting unit that transmits the signal on a predetermined channel corresponding to the selected channel group. 12. The relay station further comprises destination determining means for determining a station to be a destination of packet relay based on a reception level of a control signal or the number of hops from the base station to the own station. 7. The wireless communication system according to claim 5, wherein the wireless communication system is a wireless communication system. 13. The decoding means for the relay station to despread signals received from a mobile station, a base station and another relay station into an information sequence signal, and to spread the decoded information sequence signal. 7. The wireless communication system according to claim 5, further comprising: a spread signal generating unit that generates a spread signal according to claim 5. 14. When the relay station includes at least the transmission power amount calculation means, the transmission power calculated by the transmission power amount calculation means is allocated to the spread signal generated by the spread signal generation means, 14. The wireless communication system according to claim 13, wherein the spread signal is transmitted. 15. The channel group selecting means for selecting a transmission / reception channel group based on the number of hops from a base station to its own station, or both or one of the packet transmission directions, and a signal to be transmitted, 7. The wireless communication system according to claim 5, further comprising: a signal transmitting unit that transmits the signal on a predetermined channel corresponding to the selected channel group. 16. The relay station is configured by a station having the function of the mobile station, or a relay device installed in a vehicle or a stationary facility. Wireless communication system. 17. A base station which constitutes a wireless communication system for performing communication based on a wireless packet transmission system together with a mobile station and a relay station having a relay function for packet transmission, wherein when a packet is received, an interference level is set. An interference level measuring unit for measuring, a desired signal level calculating unit for calculating a desired signal level based on the interference level obtained by the measurement, and a desired signal for notifying the calculated desired signal level to the station on the transmitting side of the packet. A base station comprising: a signal level notifying means. 18. The base station according to claim 17, wherein the interference level measured by the interference level measuring means is an interference level at the local station of a channel group used for receiving a packet. 19. A CD as a wireless multiplexing system for packet transmission.
A base station that configures a wireless communication system using MA with a mobile station and a relay station having a relay function for packet transmission, and when receiving a packet, measures the interference level at the local station of a channel group used for reception. Interference level measuring means, a desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, and a desired signal level for notifying the calculated desired signal level to the station on the transmission side of the packet. A base station including a notification unit. 20. When transmitting a packet, a transmission power amount calculation means for calculating the transmission power amount of the packet based on a desired signal level notified from another station, and a transmission power calculated by the transmission power amount calculation means. The base station according to any one of claims 17 to 19, further comprising: a determination unit configured to determine, based on a power amount, whether or not to transmit a packet to a station that has notified the desired signal level. 21. A mobile station or a relay station, which is a destination of a packet, based on at least one of a reception level of a control signal, an interference level of its own station, and a number of hops from a station as a starting point of a transmitting side to its own station. 21. The base station according to claim 20, further comprising a transmission destination determining means for determining. 22. A affiliation that holds affiliation information of mobile stations and relay stations that can directly communicate with the own station, and affiliation information of mobile stations and relay stations that can directly communicate with the relay station without being able to communicate directly with the own station. The base station according to any one of claims 17 to 19, further comprising information holding means. 23. A channel group selection means for selecting a transmission / reception channel group based on a packet transmission direction, and a signal transmission means for transmitting a signal to be transmitted on a predetermined channel corresponding to the selected channel group. The base station according to any one of claims 17 to 19, further comprising: 24. A mobile station comprising a base station and a relay station having a relay function for packet transmission, which constitutes a radio communication system for performing communication based on the radio packet transmission method, and is notified from a station on the packet transmission side. Transmission power amount calculating means for calculating the transmission power amount of the packet based on the desired signal level, and whether or not the packet can be transmitted to the station on the transmission side based on the transmission power amount calculated by the transmission power amount calculating means. A mobile station comprising: a determination means for determining 25. When receiving a packet, interference level measuring means for measuring an interference level, desired signal level calculating means for calculating a desired signal level based on the interference level obtained by the measurement, and the calculated desired signal. The mobile station according to claim 24, further comprising: desired signal level notifying means for notifying a level to a station on a transmission side of the packet. 26. The mobile station according to claim 25, wherein the interference level measured by the interference level measuring means is an interference level in the local station of a channel group used for receiving a packet. 27. CD as a wireless multiplexing system for packet transmission
A mobile station that configures a wireless communication system using an MA together with a base station and a relay station having a relay function for packet transmission, and transmits a packet based on a desired signal level notified from the base station or the relay station. Transmission power amount calculation means for calculating the amount of power, and determination means for determining whether or not packet transmission to the station that has notified the desired signal level is possible based on the transmission power amount calculated by the transmission power amount calculation means. A mobile station comprising: 28. Based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station that is the origin of the transmitting side to the own station, a base station or a relay that is a destination of the packet. 28. The mobile station according to claim 24, further comprising a transmission destination determining unit that determines a station. 29. Channel group selection means for selecting a transmission / reception channel group based on either or both of the number of hops from the base station to the own station or the transmission direction of a packet, and the signal to be transmitted is the selected channel group. The mobile station according to any one of claims 24 to 27, further comprising: a signal transmitting unit that transmits the signal on a predetermined channel according to the above. 30. A wireless communication system for performing communication based on a wireless packet transmission system, which is configured with a base station and a mobile station, and which has a relay function for packet transmission, and which interferes when receiving a packet. Interference level measuring means for measuring the level, desired signal level calculating means for calculating the desired signal level based on the interference level obtained by the measurement, and notifying the calculated desired signal level to the station on the transmitting side of the packet And a desired signal level notifying means for performing the relay station. 31. Based on at least one of the interference level, the desired signal level, the control signal reception level, and the number of hops from the base station to the local station, it is determined whether or not the station on the transmission side can transmit a packet. 31. The relay station according to claim 30, further comprising a judging unit, wherein the desired signal level notifying unit notifies the transmitting side station of the desired signal level according to a result of the judging unit. 32. The relay station according to claim 30, wherein the interference level measured by the interference level measuring means is an interference level at a local station of a channel group used for receiving a packet. 33. CD as a wireless multiplexing system for packet transmission
A wireless communication system using MA is configured with a base station and a mobile station, and is a relay station having a relay function for packet transmission, and when a packet is received, the interference level at the local station of a channel group used for reception is set. An interference level measuring unit for measuring, a desired signal level calculating unit for calculating a desired signal level based on the interference level obtained by the measurement, and a desired signal for notifying the calculated desired signal level to the station on the transmitting side of the packet. A relay station provided with signal level notifying means. 34. When relaying a packet, a transmission power amount calculation means for calculating the transmission power amount of the packet based on a desired signal level notified from another station, and a transmission power calculated by the transmission power amount calculation means. The relay station according to any one of claims 30 to 33, further comprising: a determination unit configured to determine, based on an amount of electric power, whether to transmit a packet to a station that has notified the desired signal level. 35. A station to be a destination of packet relay is determined based on at least one of a reception level of a control signal, an interference level of its own station, and a number of hops from a station as a starting point of a transmitting side to its own station The relay station according to any one of claims 30 to 33, further comprising a transmission destination determining unit that performs the transmission. 36. Decoding means for decoding a signal received from a mobile station, a base station and another relay station into an information sequence signal by despreading, and a spread signal is generated by spreading the decoded information sequence signal. The relay station according to any one of claims 30 to 33, further comprising: 37. When the relay station comprises at least the transmission power amount calculation means, the transmission power calculated by the transmission power amount calculation means is assigned to the spread signal generated by the spread signal generation means, 37. The relay station according to claim 36, wherein the spread signal is transmitted. 38. Channel group selection means for selecting a transmission / reception channel group based on the number of hops from a station serving as a starting point on the transmission side to its own station, and a signal to be transmitted is predetermined according to the selected channel group. 34. The relay station according to any one of claims 30 to 33, further comprising: a signal transmission unit that transmits the signal on the channel. 39. The relay station is configured by a station having the function of the mobile station, or a relay device installed in a vehicle or a stationary facility.
33. The relay station according to any one of 33. 40. A packet transmission control method in a wireless communication system configured to include a base station, a mobile station, and a relay station having a relay function for packet transmission by multi-hop and performing communication based on a wireless packet transmission method. In the packet transmission, the station on the receiving side measures the interference level, and the station on the receiving side calculates the desired signal level based on the interference level obtained by the measurement. A level calculating step, a desired signal level notifying step in which the receiving station notifies the transmitting station of the calculated desired signal level, and the transmitting station is based on the notified desired signal level. A transmission power amount calculating step of calculating the transmission power amount of the packet, and the station on the transmitting side, based on the calculated transmission power amount,
The determination step of determining whether or not the packet transmission to the receiving station is possible, and the transmitting station determines the transmission power amount of the receiving station with respect to the receiving station determined to be able to transmit the packet. A packet transmission step of performing packet transmission using electric power, and a packet transmission control method comprising: 41. A wireless communication system comprising a base station, a mobile station, and a relay station having a relay function for packet transmission, wherein the wireless communication system uses CDMA as a wireless multiplexing system for packet transmission. A packet transmission control method executed when transmitting a packet to a base station via a relay station, wherein a station on the packet receiving side measures an interference level of measuring the interference level of the received packet at the local station. A desired signal level calculation step in which the receiving station calculates a desired signal level based on the interference level obtained by the measurement, and the receiving station calculates the desired signal level by transmitting the packet. A desired signal level notifying step of notifying the station on the side of the transmission, and a station of the transmitting side, a transmission power amount calculating step of calculating the transmission power amount of the packet based on the notified desired signal level. Station of the transmitting side, based on the transmission power amount calculated,
The determination step of determining whether or not the packet transmission to the receiving station is possible, and the transmitting station determines the transmission power amount of the receiving station with respect to the receiving station determined to be able to transmit the packet. A packet transmission step of performing packet transmission using electric power, and a packet transmission control method comprising: 42. The mobile station serving as the receiving station is based on at least one of the reception level of a control signal, the interference level of the own station, and the number of hops from the originating station of the transmitting side to the own station. 42. The packet transmission control method according to claim 40, further comprising a mobile station transmission destination determining step of determining a base station or a relay station that is a transmission destination of the packet. 43. Based on at least one of the reception level of the control signal, the interference level of the own station, and the number of hops from the station that is the origin of the transmitting side to the own station, 42. The packet transmission control method according to claim 40, further comprising a base station transmission destination determining step of determining a mobile station or a relay station that is a transmission destination of the packet. 44. The relay station that has become the receiving station is based on at least one of a control signal reception level, an interference level of the own station, and a hop number from the station that is the starting point of the transmitting side to the own station. 42. The packet transmission control method according to claim 40, further comprising a relay station transmission destination determining step of determining a station to be a transmission destination of packet relay. 45. A decoding step in which the relay station decodes an information sequence signal by despreading signals received from a mobile station, a base station and another relay station, and the relay station concerned decodes the decoded information sequence. 42. The packet transmission control method according to claim 40 or 41, further comprising: a spread signal generation step of generating a spread signal by spreading the signal. 46. The mobile station and the relay station select a channel group for transmission / reception based on either or both of the number of hops from a station that is a starting point on the transmission side to a local station and / or the transmission direction of a packet, and A channel group selection step in which the base station selects a transmission / reception channel group based on the packet transmission direction, and the mobile station, the relay station, and the base station transmit signals to be transmitted according to the selected channel group. The packet transmission control method according to claim 40 or 41, further comprising: a signal transmission step of transmitting the signal on a predetermined channel. 47. In the channel group selection step, a transmission channel for signal transmission is divided into two channel groups, and one channel group is commonly used by a base station, a relay station and a mobile station. 47. The packet transmission control method according to claim 46, wherein an uplink signal which is a transmission source is assigned, and the other channel group is assigned to a downlink signal whose transmission source is a base station. 48. In the channel group selection step, a transmission channel for signal transmission is divided into four channel groups, and a base station, an even-numbered relay station from the base station, and a hop count from the base station regarding a mobile station. , The first channel group is assigned to the downlink signal whose source is the base station, and the second channel group is the uplink source whose mobile station is the source. The third channel group is assigned to the downlink signal in common with the mobile station when the relay station is assigned to the signal in an odd number from the base station and the mobile station has an odd number of hops from the base station. 47. The packet transmission control method according to claim 46, characterized in that a fourth channel group is assigned to the upstream signal. 49. In the channel group selection step, transmission channels for signal transmission are divided into N (N is an integer of 3 or more) channel groups, and each of the base station, the relay station and the mobile station The N channel groups are allocated such that the same channel group is allocated to the transmitted upstream signal and the downstream signal in the station, and different channel groups are allocated to the received upstream signal and the downstream signal. 47. The packet transmission control method according to claim 46. 50. In the channel group selection step, a transmission channel for signal transmission is divided into two channel groups, and a base station, and an even-numbered relay station from the base station and a transmission from the mobile station are firstly transmitted. Second reception on the channel group
47. The packet transmission according to claim 46, characterized in that the second channel group performs the transmission from the base station to the odd-numbered relay station and the mobile station and the first channel group performs the reception from the base station. Control method. 51. The packet transmission control method according to claim 47, wherein the channel group is configured by channel groups divided by frequency. 52. The packet transmission control method according to claim 47, wherein the channel group is configured by channel groups divided by time. 53. The packet transmission control method according to claim 48, wherein the channel group is configured by channel groups divided by both frequency and time.