JP3526254B2 - Configuration of Downlink Channel in Multicarrier / DS-CDMA Mobile Communication System - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a multi-carrier /
DS-CDMA (Direct Sequence-Code Divisional Mu)
ltiple Access) The present invention relates to a downlink channel configuration in a mobile communication system.
The present invention relates to a downlink channel configuration that enables efficient transmission of information from a base station to a mobile device of each user in an MA mobile communication system.

[0002]

2. Description of the Related Art Currently, digital mobile communication systems (PD
C system, GSM system, etc.) are mainly voice communication services, and system design is based on circuit switching. A packet transmission service is planned for the next-generation mobile phone system (IMT-2000), which will be introduced in the future, but a system design based on circuit switching is still being performed. In this way, in the wireless transmission system based on circuit switching, the number of channels of the upper and lower lines is almost equal, and the channel configuration of upper and lower sides is set even when performing data communication. Therefore, the transmission of the control command to each user is performed using the channel corresponding to each user.

[0003]

On the other hand, multimedia mobile communication, which is expected to grow in demand in the future, has vertically asymmetric communication. That is, when downloading data, most of the traffic is downlink, and when uploading the data, most of the traffic is uplink and only the response signal is required for downlink. In such a case, if one channel assigned to each user is used to send the control command of each user, the efficiency of information transmission becomes poor.

On the other hand, multi-carrier / DS-CDMA
(Direct Sequence Code Division Multiple Access)
Mobile communication systems have recently been attracting attention as mobile communication systems that enable high-speed transmission of information. In this multi-carrier / DS-CDMA mobile communication system, regarding the configuration of the downlink channel in consideration of the asymmetrical information transmission amount in the uplink and downlink as described above when performing high-speed data communication for multimedia etc. , No proposal has been made so far.

Therefore, an object of the present invention is to provide a downlink channel structure in a multi-carrier / DS-CDMA mobile communication system which can efficiently transmit control information to each user even in a situation where the amount of transmission information is vertically asymmetric. It is to be.

[0006]

In order to solve the above-mentioned problems, according to the present invention, as described in claim 1, the information symbol is band-expanded by a spreading code sequence, and the spreading code obtained by the band expansion is used. Multicarrier / DS-C transmitting using a plurality of subcarriers having a predetermined frequency interval
In the configuration of a downlink channel in a DMA mobile communication system, a plurality of communication channels assigned to each of a plurality of subcarriers are divided into predetermined time frames and multiplexed, and user-specific control information and user common
Generate at least one of the control information of the
In this case, the generated control information is stored in the plurality of subkeys.
Of the communication channels assigned to each carrier
Included in the communication channels, and the included communication channels are common
It is characterized by being configured as a control channel.

Such multi-carrier / DS-CDM
A According to the configuration of the downlink channel in the mobile communication system, when transmitting information from the base station to each user (mobile device), each of the above-mentioned subcarriers can be either unique information or common information for each user. , And can be transmitted by being included in the common control channel.

[0008] From the viewpoint that the information used when each user transmits information to the base station can be efficiently transmitted to each user, the present invention is as described in claim 2. In the configuration of the downlink channel, the common control channel may include information on a response to each user's uplink transmission as the user-specific control information .

The information for controlling the uplink transmission of each user is, for example, a transmission power control command used for controlling the transmission power of each user (mobile device), or for controlling the user's call origination. It may include control commands used, control commands used to control which frequency, code (including spreading factor), and time each user uses for transmission.

From the viewpoint that the response to the information transmitted from each user can be efficiently transmitted to each user, the present invention provides the common control channel in the configuration of the downlink channel as described in claim 3. in the information of a response to uplink transmission of each user, the user solid
It can be included as existing control information .

The information of the response to each user's uplink transmission is, for example, a response signal ACK (Acknowledgement) or NACK (Non-acknowledgment) to the uplink communication.
gement) can be included.

According to the present invention, as described in claim 4, from the viewpoint that the broadcast information to be commonly notified to each user can be efficiently transmitted, in the downlink channel configuration, the common control channel is used. In addition, the common notification information for each user can be included as the control information common to the user .

The broadcast information for each user can include, for example, time, cell (base station) information, traffic information of its own cell, traffic information, broadcast information such as television, and the like.

From the viewpoint of ensuring that the downlink signal can be demodulated based on the state of the radio transmission line between the base station and the user, the present invention is as described in claim 5.
In the configuration of the downlink channel, the common control channel may include pilot symbols used for demodulating a received signal in each user as control information common to the users .

Further, according to the present invention, as described in claim 6, in the configuration of each of the downlink channels, a common control channel for one or a plurality of code channels in a part or all of the plurality of subcarriers is provided. Can be assigned.

Further, according to the present invention, as described in claim 7, in the configuration of each of the downlink channels, the type of information included in the common control channel in each subcarrier can be different.

Further, according to the present invention, as described in claim 8, in the configuration of each downlink channel, the information included in the common control channel assigned to each subcarrier is a part of each time frame. Can be time multiplexed.

10. When the information included in each common control channel is time-multiplexed on a part of each time frame,
Alternatively, each subcarrier may be time-multiplexed to the same timing portion of each time frame, as described in claim 10, wherein each subcarrier has a different timing portion of each time frame. It can also be time multiplexed.

[0019]

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

A base station that transmits information to each user in the downlink channel configuration according to the embodiment of the present invention is configured as shown in FIG. 1, for example. This base station uses multi-carrier / DS-CDMA as an access method.
(Direct Sequence-Code Division Multiple Access)
The method is adopted.

In FIG. 1, this base station includes a common control channel generator 11 and a user channel generator 12 (# 1).
.About.12 (#m), a multiplexing unit 13, a multicarrier modulation unit 14, and a transmission unit 15. The common control channel generation unit 11 expands the band of the control information symbol for each user with a specific spreading code sequence, and generates a spread signal corresponding to the control information symbol. Each of the user channel generation units 12 (# 1) to 12 (#m) band-expands the information symbol to be transmitted to each user with a spreading code sequence corresponding to each user, and spreads a signal corresponding to the information symbol. To generate.

The multiplexing section 13 synthesizes the spread signals corresponding to the information symbols from the respective user channel generating sections 12 (# 1) to 12 (#m), and then shares the same signal with the signal obtained by the synthesis. The spread signal corresponding to the control information symbol from the control channel generation unit 11 is multiplexed according to a predetermined algorithm. This multiplexing algorithm can be set arbitrarily. For example, any one of time-multiplexing that inserts information periodically at a fixed time, frequency-multiplexing that inserts information in a specific subcarrier, and code-multiplexing that uses a specific code or a combination thereof. Information can be multiplexed by any combination.

The multi-carrier modulator 14 is the multiplexer 1
Modulation (inverse discrete Fourier transform: IDFT) is performed so that the multiplexed signal from 3 is dispersed into a plurality (n) of subcarrier (multicarrier) components. Then, the signals including the plurality of subcarrier components obtained by the multicarrier modulation unit 14 are sequentially transmitted to the transmission unit 15, and the transmission unit 15 transmits the signals to each user (mobile station). . The frequency intervals of the subcarriers used in the multicarrier modulation unit 14 are the common control channel generation unit 11 and each user channel generation unit 12 (# 1) to
12 (#m) is set to p times (p: positive real number) the update frequency (chip rate) of each spreading code sequence.

The common control channel generator 11 is constructed, for example, as shown in FIG.

In FIG. 2, the common control channel generator 11 includes an uplink transmission control information generator 20 and a combiner 60.
have. The uplink transmission control information generation unit 20
The transmission power control information generating unit 21, the first transmission control information generating unit 22, and the second transmission control information generating unit 2 are used to generate information for controlling transmission from each user (mobile station).
3, a channel allocation information generating unit 24 and a synthesizing unit 25.

The transmission power control information generation unit 21 generates a transmission power control command for a user who controls uplink transmission power. The first transmission control information generation unit 22 generates control information such as a frequency assigned to random access, the number of codes, a time slot, and a transmission permission probability of random access based on traffic information and the like. The second transmission control information generation unit 23, based on the traffic information and the like,
The control information such as the frequency assigned to the reservation packet, the number of codes, the time slot, and the transmission permission probability of random access is generated. The channel allocation information generation unit 24 generates information such as a frequency, a code (including a spreading factor), a time slot, etc., to be assigned to a user who receives a reservation packet and permits transmission.

The transmission power control command from the transmission power control information generating unit 21 differs depending on the state of the communication transmission path with each user (mobile station), and is control information unique to each user. On the other hand, the first transmission control information generation unit 22
Also, the respective control information from the second transmission control information generating unit 23 and the information regarding the channel allocation from the channel allocation information control unit 24 are common to all users.

The synthesizing unit 25 is the transmission power control information generating unit 2
Information bits from the first transmission control information generation unit 22, the second transmission control information generation unit 23, and the channel allocation information generation unit 24 are combined according to a predetermined algorithm.
The combined signal obtained by the combining unit 25 is output from the uplink transmission control information generating unit 20 as information for controlling the uplink transmission. The control information from the uplink transmission control information generating unit 20 and other common control information are combined by the combining unit 60.
And the combined signal is output from the common control channel generation unit 11 as information for controlling transmission from each user.

In the above description, the process for expanding the band by the spread code is omitted, but the process for expanding the band by the spread code sequence of the combined signal is performed in the subsequent stage of the combining unit 60. That is, as described above, the control information is output from the common control channel generation unit 30 as a spread signal.

The common channel generation unit 11 can be further configured to have a response information generation unit 30 as shown in FIG.

In FIG. 3, the response information generation unit 30 generates response information for uplink transmission from each user, and user response information generation units 31 (1) to 31 (m) corresponding to each user. And a synthesizing section 32. Each of the user response information generation units 31 (1) to 31 (m) sends a response command ACK to the upstream packet from the corresponding user.
(Acknowledgement) or NACK (Non-acknowledge)
ment) is generated. The synthesizing unit 32 synthesizes the information bits related to the response commands from the user response information generating units 31 (1) to 31 (m) according to a predetermined algorithm.

The combined signal from the combining unit 32 is output from the response information generating unit 30 as the response information for the uplink transmission. Then, the response information is combined with other common control information (which may include the control information from the uplink transmission control information generating unit 20 shown in FIG. 2) in the combining unit 60.

The common channel generator 11 is further further provided with:
As shown in FIG. 4, it can be configured to have a common notification information generation unit 40.

In FIG. 4, the common notification information generation unit 40
Has a time information generation unit 41, a cell information generation unit 42, a traffic information generation unit 43, a traffic information generation unit 44, a broadcast information generation unit 45, and a synthesis unit 46. The time information generation unit 41 generates time information indicating absolute time.
The cell information generation unit 42 generates information about a base station such as ID information identifying the cell (base station), information indicating the position of the base station, information indicating a base station existing in the vicinity of the base station. .

The traffic information generator 43 generates traffic information based on the upstream and downstream communication conditions in its own cell. The traffic information generation unit 44 uses the cell (base station)
Generates traffic information that represents the traffic conditions on the surrounding roads. The broadcast information generation unit 45 uses the TV information,
Generate information such as peripheral information.

The above-mentioned information generation units 41, 42, 43, 4
No. 4, 45 need not generate information in synchronization. The information can be generated at different cycles depending on the type of information.

As described above, the information generation units 41, 4
The information bits generated by one or more of 2, 43, 44, and 45 are combined by the combining unit 46 according to a predetermined algorithm. The combined signal from the combining unit 46 is output from the common notification information generation unit 40 as common notification information. The common broadcast information includes other common control information (control information from the uplink transmission control information generation unit 20 shown in FIG. 2 and / or response information from the response information generation unit 30 shown in FIG. 3 or both. May be used), and is combined in the combining unit 60.

The common channel generator 11 can also be configured as shown in FIG.

In FIG. 5, the common control channel generator 11 includes a pilot symbol generator 50 and a combiner 60.
have. The pilot symbol generator 50 generates a known pilot symbol that is commonly used by all users for synchronization, channel estimation, and the like.
The pilot symbols from the pilot symbol generator 50 are other common control information (control information from the uplink transmission control information generator 20 shown in FIG. 2, response information from the response information generator 30 shown in FIG. 3, and FIG. May be included in the common notification information from the common notification information generation unit 40 shown in FIG.

The configuration of the downlink channel formed by the base station adopting the multi-carrier / DS-CDMA system configured as described above is as shown in FIG. 6, for example.

In the example of FIG. 6, a common control channel is assigned to one code channel in each of the n subcarriers 1 to n and a communication channel is assigned to a plurality of code channels in each time frame that is a predetermined time. It is assigned. Each channel (common control channel and communication channel) in each subcarrier is the above-mentioned common control channel generation unit 11 and user channel generation unit 1.
2 (# 1) to 12 (#m) are distinguished by the spread code sequence (code).

The common control channel includes information generated by the common control channel generation unit 11, for example, pilot symbols (generated by the pilot symbol generation unit 50), control information for controlling uplink transmission (uplink transmission). Control information generation unit 20), response information for uplink transmission (generated by response information generation unit 30), common notification information (common notification information generation unit 40), or
Any combination thereof is included.

Information (transmission data) to be transmitted to the user is assigned to each communication channel, and the communication generated by the user channel generation units 12 (# 1) to 12 (#m) corresponds to the communication. It will be included in the channel.

It should be noted that a communication channel in one or a plurality of subcarriers can be assigned to each user.

In the downlink channel configuration as described above, it is possible to arbitrarily set what information is included in the common control channel in each subcarrier or whether information is included in the common channel in all subcarriers. .

Similarly to the example shown in FIG. 6, in each time frame, a common control channel is assigned to one code channel and communication channels are assigned to a plurality of code channels in each of the n subcarriers 1 to n. Another configuration example of the assigned downlink channel will be described.

In the example shown in FIG. 7, information other than pilot symbols (uplink control information, uplink response information,
Broadcast information) is included in the common control channel in a specific subcarrier (for example, subcarrier 1). The pilot symbol may be included in the common control channel for all subcarriers or may be included in the common control channel for each discrete subcarrier.

In the example shown in FIG. 8, the subcarriers to which the common control channel to include the information is assigned are changed according to the type of information. For example, the uplink control information is included in the common control channel in subcarrier 1, the uplink response information is included in the common control channel in subcarrier 2, and the broadcast information is included in the common control channel in subcarrier n. This example also
Similar to the example shown in FIG. 7, the pilot symbol may be included in the common control channel in all subcarriers or in the common control channel in each discontinuous subcarrier.

In the example shown in FIG. 9, any one of the pilot symbols, the uplink control information, the uplink response information, and the broadcast information, or any one of them in the predetermined time zone T, not in the entire time frame. The combination is included in the common control channel on each subcarrier. As a result, the information contained in the common control channel in each subcarrier is transmitted at the same timing in each predetermined cycle.

In the example shown in FIG. 10, similar to the example shown in FIG. 9, the above-described information is included in the common control channel in each subcarrier in a part of the time frame instead of the entire time frame. . Particularly, in this case, the time zones T1, T2, ..., Tn are different for each subcarrier.
As a result, the information contained in the common control channel in each subcarrier is transmitted at a predetermined timing in each predetermined cycle.

Multi-carrier / DS-C as described above
According to the configuration of the downlink channel in the DMA mobile communication system, various information can be transmitted to each user including the information in the common control channel that can be commonly used by all users. As compared with the case where the information is transmitted through the channel unique to the user, the information can be efficiently transmitted.

In particular, if information common to each user (for example, transmission power control information, response information to each user, channel allocation information, etc.) is included in the common control channel, information unique to a plurality of users can be combined into one. It becomes possible to transmit on the common control channel, which enables efficient transmission of information.

In each of the above-mentioned examples, the common control channel is assigned to one code channel in all subcarriers, but the present invention is not limited to this. It is possible to assign a control channel to one or more code channels in some or all of the plurality of subcarriers.

[0054]

As described above, according to the present invention of claims 1 to 10, multi-carrier / DS
-In a CDMA mobile communication system, when transmitting information from a base station to each user (mobile device), both unique information and common information for each user are included in the common control channel in each subcarrier. Can be sent. Therefore, multi-carrier / DS-C
In the DMA mobile communication system, the control information for each user can be efficiently transmitted even in a situation where the amount of transmission information is vertically asymmetric.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a base station according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a first configuration example of a common control channel generation unit.

FIG. 3 is a block diagram showing a second configuration example of a common control channel generation unit.

FIG. 4 is a block diagram showing a third configuration example of a common control channel generation unit.

FIG. 5 is a block diagram showing a fourth configuration example of a common control channel generation unit.

FIG. 6 is a diagram showing a first configuration example of a downlink channel.

FIG. 7 is a diagram showing a second configuration example of a downlink channel.

FIG. 8 is a diagram showing a third configuration example of a downlink channel.

FIG. 9 is a diagram showing a fourth configuration example of a downlink channel.

FIG. 10 is a diagram illustrating a fifth configuration example of a downlink channel.

[Explanation of symbols]

11 Common control channel generator 12 (# 1) to 12 (#m) user channel generation unit 13 Multiplexing unit 14 Multi-carrier modulator 15 Transmission unit 20 Uplink transmission control information generation unit 21 Transmission power control information generator 22 First Transmission Control Information Generation Unit 23 Second Transmission Control Information Generator 24 channel allocation information generator 25 Composition Department 30 Response Information Generation Unit 31 (1) to 31 (m) user response information generation unit 32 Synthesis Department 40 Common Broadcast Information Generation Unit 41 Time information generator 42 Cell information generator 43 Traffic Information Generation Unit 44 Traffic information generator 45 Broadcast information generator 46 Composition Department 50 Pilot symbol generator 60 synthesis section

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04Q 7/30 (72) Inventor Fumiyuki Adachi 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Shares In-house (56) Reference JP-A-9-327073 (JP, A) International publication 96/037079 (WO, A1) 3GPP2 C.I. S0002-0, Physical Layer Standard for cdma2000 Spre ad Spectrum Systems, July 1999, Version 1.0, all pages, URL, http: // www. 3 gpp2. org / Public_html / specs / C. S0002-0_vl. 0. pdf (58) Fields investigated (Int.Cl. ⁷ , DB name) H04J 13/00-13/06 H04B 1/69-1/713 H04J 1/00 H04B 7/24-7/26 H04Q 7/00- 7/38

Claims (10)

(57) [Claims] 1. A multicarrier / DS-CDMA mobile communication system for expanding a band of an information symbol by a spreading code sequence and transmitting a spreading code obtained by the band expansion using a plurality of subcarriers having a predetermined frequency interval. In the configuration of the downlink channel in (1), the plurality of communication channels assigned to each of the plurality of subcarriers are delimited at predetermined time frames and multiplexed, and control information unique to the user and control information common to the users are reduced.
If at least one is generated and asymmetric communication is performed, the generated control information is
The communication channel assigned to each of the multiple subcarriers
Included in any of the channel's communication channels
Configuration of a downlink channel in a multicarrier / DS-CDMA mobile communication system in which the channel is configured as a common control channel . 2. The downlink channel configuration according to claim 1, wherein the common control channel includes information for controlling uplink transmission of each user and control information unique to the user.
Multi-carrier / DS-CDMA which is adapted to include
Configuration of downlink channel in mobile communication system. 3. The downlink channel configuration according to claim 1 or 2, wherein information on a response to each user's uplink transmission is set as the user-specific control information on the common control channel.
The configuration of the downlink channel in the multi-carrier / DS-CDMA mobile communication system that is included in the above. 4. The downlink channel structure according to claim 1, wherein the common control channel includes common broadcast information for each user as control information common to the users. -Downlink channel configuration in a CDMA mobile communication system. 5. The downlink channel structure according to claim 1, wherein a pilot symbol used for demodulating a received signal at each user is shared by the users on the common control channel .
Multicarrier / DS-included as control information
Configuration of downlink channel in CDMA mobile communication system. 6. The downlink carrier structure according to claim 1, wherein a common control channel is assigned to one or a plurality of code channels in a part or all of the plurality of subcarriers. / DS-CDMA mobile communication system downlink channel configuration. 7. The downlink carrier structure according to any one of claims 1 to 6, wherein the types of information included in the common control channel in each subcarrier are different.
Configuration of downlink channel in MA mobile communication system. 8. The downlink channel configuration according to claim 1, wherein the information included in the common control channel assigned to each subcarrier is time-multiplexed in a part of each time frame. Configuration of downlink channel in carrier / DS-CDMA mobile communication system. 9. The downlink channel structure according to claim 8, wherein the information included in the common control channel assigned to each subcarrier is time-multiplexed on the same timing portion of each time frame in each subcarrier. Of a downlink channel in the multi-carrier / DS-CDMA mobile communication system described above. 10. The downlink channel structure according to claim 8, wherein the information included in the common control channel assigned to each subcarrier is time-multiplexed to a different timing portion of each time frame in each subcarrier. Of a downlink channel in the multi-carrier / DS-CDMA mobile communication system described above.