CN100479595C - Soft handover resource assignment method and system - Google Patents

Abstract

The present invention provides a soft handover resource assignment method, including the following steps: first step, one or more specific sectors in the serving sector set send a soft handover resource assignment message to the access terminal, wherein the soft handover resource The assignment message carries all channel resource allocation information in the serving sector set; and in the second step, in response to the soft handover resource assignment message, the access terminal performs data processing according to the channel resource allocation information in the soft handover resource assignment message transmission. In addition, the invention also provides a soft handover resource assignment system. Through the above technical solutions, the present invention achieves the following beneficial effects: the overhead of the system control channel is reduced, the interference caused by assignment messages is reduced, and the system can efficiently meet the assignment needs of soft handover users, thereby improving the throughput of the entire system quantity.

Description

Soft handover resource assignment method and system

technical field

The present invention relates to the communication field, and more particularly, relates to a soft handover resource assignment method and system, which can be applied to such as wireless communication packet switching systems.

Background technique

Mobile communication system is one of the hotspots in communication technology research at present. With the evolution and development of mobile communication technology, broadband and IP packet switching are the main development trends. In the current research of 3G (third generation mobile communication), 3.5G and 4G, higher throughput and higher spectral efficiency have become one of the research focuses.

There are many ways to achieve higher throughput and higher spectral efficiency, including the introduction and realization of various diversity techniques, one of which is to increase the effective bandwidth for data transmission in the communication bandwidth more effectively. In a mobile communication system, control channels are usually used to carry various control signaling, and data channels are used to carry effective service data transmission. Therefore, how to design an efficient communication system, under the premise of ensuring the normal and effective operation of the system, reduce the overhead of the control channel as much as possible, so as to increase the occupation ratio of the service channel and improve the throughput of the entire system, is always an important research topic.

The OFDMA (access scheme based on Orthogonal Frequency Division Multiplexing) system uses OFDM (Orthogonal Frequency Division Multiplexing) technology as a multiplexing technology, that is, it distinguishes the multiplexing of different users by allocating different data subcarriers to different users. Use transmission technology. Since data transmission between users uses different mutually orthogonal subcarriers, data transmission between users in the same cell will not interfere with each other. Moreover, when allocating subcarriers, the wireless environment conditions of the user can be fully utilized, frequency selectivity can be fully utilized, and the most suitable data subcarriers for transmission can be allocated to users, so that the capacity of the entire system can be further improved.

In an OFDM or OFDMA system, since intra-cell interference is basically eliminated, inter-cell interference becomes the main interference. In order to solve the problem of lower service quality and lower throughput of cell edge users due to the possible interference, it is a common method to improve the service quality of these users through soft handover or similar means, such as implementing in different sectors of a base station Softer handover, implement ordinary soft handover between different base stations or implement soft handover by maintaining an active set and several soft handover groups (SHOG) for each AT (Access Terminal, access terminal).

In the packet-switched mobile communication system currently commercially available and being researched by the industry, since each user's downlink or uplink data request is bursty and distributed, the resource allocation for each user is based on the user's request Uplink and downlink are performed separately, especially for systems using OFDM or OFDMA technology.

Specifically, in the design of the control channel, when there is downlink data that needs to be sent to the user and the downlink channel resource is allocated to the user, the system notifies the user by sending a downlink channel assignment message, and the user occupies the corresponding resource for downlink according to the message. Data reception and processing; when the user has uplink data to send and allocates uplink channel resources for the user, the system notifies the user by sending an uplink channel assignment message, and the user occupies the corresponding resources according to the message to prepare and send uplink data; Figure 1 shows a typical assignment message design, including the design of a downlink assignment message and an uplink assignment message.

In the case of implementing downlink soft handover technology, each base station in the active set that needs to provide services for the current AT needs to send the same data to the current AT at the same time and frequency resources, and the AT performs data combination to obtain the corresponding soft handover gain; In the case of implementing the uplink soft handover technology, the AT sends data in the assigned time and frequency resources, and each base station in the active set that needs to provide services for the current AT receives the data and performs corresponding combination processing to obtain the soft handover gain. Therefore, regardless of downlink or uplink soft handover, each base station that provides services to users needs to send downlink or uplink assignment messages to the current AT through their respective forward control channels, telling the current AT the specific situation of assigned resources.

In the technical solution according to the related art, since there is more than one base station serving the current user at the same time in the case of soft handover, the same number of assignments as the serving base station is required for a downlink or uplink resource allocation for the current user The message can accomplish the purpose. With the continuous increase of the user's time in soft handover or the continuous increase of users in the soft handover state, the resource allocation overhead of the entire system will continue to increase, and at the same time, the assignment efficiency will decrease accordingly (because multiple assignment messages are required The behavior of assigning resources for a user can be completed), which also causes the control channel load to remain high, thereby affecting the further improvement of the throughput and performance of the entire system.

Therefore, there is a need for a soft handover resource assignment method and system, which can reduce the overhead of the system control channel, reduce the interference caused by assignment messages, enable the system to efficiently meet the assignment needs of soft handover users, and improve the throughput of the entire system quantity.

Contents of the invention

The present invention has been made in consideration of the above-mentioned problems. The present invention provides a soft handover resource assignment method and system, which can reduce the overhead of the system control channel, reduce the interference caused by the assignment message, thereby improving the throughput of the entire system, and it can be applied to such as wireless Communication packet switching system.

According to one aspect of the present invention, a soft handover resource assignment method is provided.

The resource assignment method according to the present invention includes the following steps: one or more specific sectors in the serving sector set send a soft handover resource assignment message to the access terminal, wherein the soft handover resource assignment message carries the serving sector All channel resource allocation information is collected; and in response to the soft handover resource assignment message, the access terminal performs data transmission according to the channel resource allocation information in the soft handover resource assignment message.

Generally, the specific sector that sends the soft handover resource assignment message is the sector with the strongest pilot strength or the sector with the best wireless environment.

In particular, the above soft handover resource assignment message carries indication information, which is used to indicate the set of serving sectors, that is, used to indicate the sectors in the set of serving sectors assigned this time. In addition, the sectors in the sector set can be represented in various ways, for example, the indication information can be the sector ID, the sector PN that uniquely identifies the sector, and the active ID that uniquely identifies the sector in the active set. set index, or a bitmap field (where each sector corresponds to one bit).

The following will specifically describe the case where the above indication information is a bitmap field. In the case where the above indication information is a bitmap field, each sector occupies one bit, for example, a bit of 0 indicates that the current sector is not in the serving sector set, on the contrary, a bit of 1 indicates that the current sector is in the serving sector set . In addition, the order of the bitmap can be uniquely identified by multiple means such as the index of the active set or the sequence number arrangement of the serving sectors. In particular, since the indication information already implies that the sector sending the soft handover resource assignment message is included in the set of serving sectors, the bitmap field preferably does not include the identification of the sector sending the message, so as to save resources.

In addition, the data transmission performed by the access terminal according to the channel resource allocation message in the soft handover resource assignment message may be receiving downlink data or sending uplink data. And in this step, the access terminal can perform soft handover data transmission in all directions, including but not limited to downlink and uplink.

In the above soft handover resource assignment method, when the access terminal receives downlink data or sends uplink data, the indication information carried in the soft handover resource assignment message is different from each other. This is because the downlink is for the base station to send data to the access terminal, so the access terminal needs to know which base stations are currently sending data to itself, so as to make full use of the combining gain brought by soft handover; while the uplink is for the access terminal to send data to the base station, Therefore, in some cases, the access end does not need to know which base stations receive the data sent by itself, only the base stations and the network side themselves need to know. Therefore, in this case, the resource assignment message indicating the reverse soft handover may not Carries a bitmap field representing the set of serving sectors.

According to another aspect of the present invention, a resource allocation system is provided.

The resource assignment system according to the present invention includes: a message sending module for sending a soft handover resource assignment message, wherein the soft handover resource assignment message carries all channel resource assignment information in the serving sector set; and a data transmission module , in response to the soft handover resource assignment message, perform data transmission according to the channel resource allocation information in the soft handover resource assignment message.

It should be noted that the above soft handover resource assignment message carries indication information for indicating the set of serving sectors, that is, for indicating the sectors in the set of serving sectors assigned this time. In addition, the sectors in the sector set can be represented in various ways, for example, the indication information can be the sector ID, the sector PN that uniquely identifies the sector, and the active ID that uniquely identifies the sector in the active set. set index, or a bitmap field (where each sector corresponds to one bit).

In the case where the above indication information is a bitmap field, each sector occupies one bit, for example, a bit of 0 indicates that the current sector is not in the serving sector set, on the contrary, a bit of 1 indicates that the current sector is in the serving sector set . In addition, the order of the bitmap can be uniquely identified by multiple means such as the index of the active set or the sequence number arrangement of the serving sectors. In particular, since the indication information already implies that the sector sending the soft handover resource assignment message is included in the set of serving sectors, the bitmap field preferably does not include the identification of the sector sending the message, so as to save resources.

In particular, the data transmission performed by the data transmission module according to the channel resource allocation information in the soft handover resource assignment message may be receiving downlink data or sending uplink data. In addition, the data transmission module can perform soft handover data transmission in all directions, including but not limited to downlink and uplink.

When the data transmission module receives downlink data or sends uplink data, the indication information carried in the soft handover resource assignment message is different from each other. Specifically, when the data transmission module sends uplink data, the soft handover resource assignment message Bitmap fields may not be included in .

Through the above technical solutions, the present invention achieves the following beneficial effects: the overhead of the system control channel is reduced, the interference caused by assignment messages is reduced, and the system can efficiently meet the assignment needs of soft handover users, thereby improving the throughput of the entire system quantity.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a diagram illustrating an exemplary soft handover resource assignment message design according to the related art;

Fig. 2 is a schematic diagram showing the design of an exemplary downlink soft handover resource assignment message according to the present invention;

FIG. 3 is a schematic diagram showing the design of an exemplary uplink soft handover resource assignment message according to the present invention;

FIG. 4 is a flow chart showing a soft handover resource assignment method according to the first embodiment of the present invention; and

FIG. 5 is a block diagram showing a soft handover resource assignment system according to a second embodiment of the present invention.

Detailed ways

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First refer to FIG. 2 to FIG. 4, wherein FIG. 2 and FIG. 3 are schematic diagrams showing the design of a downlink soft handover resource assignment message and an uplink soft handover resource assignment message respectively, and FIG. Flowchart of the resource allocation method for .

As shown in Figure 4, in step S402, a specific sector in the set of serving sectors (the sector with the strongest pilot strength or the sector with the best wireless environment) sends a soft handover resource assignment message to the access terminal, wherein , the soft handover resource assignment message carries all channel resource assignment information in the serving sector set, and includes indication information;

Wherein, the sector that sends the soft handover resource assignment message is not necessarily the sector with the strongest pilot strength or the specific sector of the sector with the best wireless environment, and one or more sectors can also send the soft handover resource assignment message. soft handover resource assignment message;

In particular, the indication information carried in the above soft handover resource assignment message is used to indicate the set of serving sectors, that is, to indicate the sectors in the set of serving sectors assigned this time. In addition, the sectors in the sector set can be represented in various ways, for example, the indication information can be the sector ID, the sector PN that uniquely identifies the sector, and the active ID that uniquely identifies the sector in the active set. A set index, or a bitmap field (wherein each sector corresponds to a bit);

In the case where the above indication information is a bitmap field, each sector occupies one bit, for example, a bit of 0 indicates that the current sector is not in the serving sector set, on the contrary, a bit of 1 indicates that the current sector is in the serving sector set . In addition, the order of the bitmap can be uniquely identified by multiple means such as the index of the active set or the sequence number arrangement of the serving sectors. In particular, since the indication information already implies that the sector sending the soft handover resource assignment message is included in the set of serving sectors, the bitmap field preferably does not include the identification of the sector sending the message, so as to save resources. Generally, the maximum number of active sets is 6, and the maximum number of serving sector sets commonly used in actual systems is 3, so only 3 bits are needed for the bitmap field.

Next, in step S404, in response to the soft handover resource assignment message, the access terminal performs data transmission according to the channel resource allocation information in the soft handover resource assignment message;

In particular, the data transmission performed by the access terminal in step S404 may be receiving downlink data or sending uplink data. In addition, the access terminal may perform soft handover data transmission in various directions, including but not limited to downlink and uplink;

In the case that the access end receives downlink data or sends uplink data in step S404, the indication information carried in the soft handover resource assignment message is different from each other. This is because the downlink is for the base station to send data to the access terminal, so the access terminal needs to know which base stations are currently sending data to itself, so as to make full use of the combining gain brought by soft handover; while the uplink is for the access terminal to send data to the base station, Therefore, in some cases, the access end does not need to know which base stations receive the data sent by itself, only the base stations and the network side themselves need to know. Therefore, in this case, the resource assignment message indicating the reverse soft handover may not Carries a bitmap field representing the set of serving sectors.

second embodiment

The second embodiment according to the present invention will be described below with reference to FIG. 5, wherein FIG. 5 is a block diagram showing a soft handover resource assignment system according to the second embodiment of the present invention.

As shown in FIG. 5 , a soft handover resource assignment system 500 according to the present invention includes a message sending module 502 and a data transmission module 504 . Wherein, the message sending module 502 is used to send a soft handover resource assignment message, wherein, the soft handover resource assignment message carries all channel resource assignment information in the serving sector set; in response to the soft handover resource assignment message, the data transmission module 504 Perform data transmission according to channel resource allocation information in the soft handover resource assignment message.

The data transmission performed by the data transmission module 504 may be receiving downlink data or sending uplink data, and in particular, the data transmission module 504 may perform soft handoff data transmission in various directions, including but not limited to downlink and uplink.

Similar to the first embodiment, the above soft handover resource assignment message carries all channel resource assignment information in the serving sector set and includes indication information. Wherein, the indication information is used to indicate the set of serving sectors, that is, used to indicate the sectors in the set of serving sectors assigned this time. In addition, the sectors in the sector set can be represented in various ways, for example, the indication information can be the sector ID, the sector PN that uniquely identifies the sector, and the active ID that uniquely identifies the sector in the active set. set index, or a bitmap field (where each sector corresponds to one bit).

In the case where the above indication information is a bitmap field, each sector occupies one bit, for example, a bit of 0 indicates that the current sector is not in the serving sector set, on the contrary, a bit of 1 indicates that the current sector is in the serving sector set . In addition, the order of the bitmap can be uniquely identified by multiple means such as the index of the active set or the sequence number arrangement of the serving sectors. In particular, since the indication information already implies that the sector sending the soft handover resource assignment message is included in the set of serving sectors, the bitmap field preferably does not include the identification of the sector sending the message, so as to save resources.

In addition, when the data transmission module 504 receives downlink data or sends uplink data, the indication information carried in the soft handover resource assignment message is different from each other. Specifically, when the data transmission module sends uplink data, the soft handover resource The bitmap field may not be included in the assignment message.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (17)

1. A soft handover resource assignment method, characterized in that, comprising the following steps: One or more specific sectors in the serving sector set send a soft handover resource assignment message to the access terminal, wherein the soft handover resource assignment message carries all channel resource allocations in the serving sector set Information and indication information for indicating the sectors in the set of serving sectors, wherein the specific sector is the sector with the strongest pilot strength or the sector with the best wireless environment; and In response to the soft handover resource assignment message, the access terminal performs data transmission according to the channel resource allocation information in the soft handover resource assignment message. 2. The soft handover resource assignment method according to claim 1, wherein the indication information is a sector ID. 3. The soft handover resource assignment method according to claim 1, wherein the indication information is a sector PN that uniquely identifies a sector. 4. The soft handover resource assignment method according to claim 1, wherein the indication information is an active set index that uniquely identifies a sector in the active set. 5. The soft handover resource assignment method according to claim 1, wherein the indication information is a bitmap field, and each sector corresponds to one bit. 6. The soft handover resource assignment method according to claim 5, wherein when the bitmap field is 1, it indicates that the corresponding sector is in the set of serving sectors, when the bitmap field When the field is 0, it means that the corresponding sector is not in the set of serving sectors. 7. The soft handover resource assignment method according to claim 5, wherein the bitmap field does not include an identifier corresponding to a specific sector that sends the soft handover resource assignment message. 8. The soft handover resource assignment method according to claim 1, wherein the data transmission by the access terminal according to the channel resource allocation information in the soft handover resource assignment message comprises: the The access terminal receives downlink data or sends uplink data according to the channel resource allocation information in the soft handover resource assignment message. 9. The soft handover resource assignment method according to claim 5 or 8, wherein when the data transmission performed by the access terminal is to send uplink data, the soft handover resource assignment message The bitmap field is not included in the . 10. A soft handover resource assignment system, characterized in that it comprises: A message sending module, configured to send a soft handover resource assignment message, wherein the soft handover resource assignment message carries all channel resource allocation information in the serving sector set and is used to indicate the channel resource allocation information in the serving sector set the indication information of the sector; and The data transmission module, in response to the soft handover resource assignment message, performs data transmission according to the channel resource allocation information in the soft handover resource assignment message. 11. The soft handover resource assignment system according to claim 10, wherein the indication information is a sector ID. 12. The soft handover resource assignment system according to claim 10, characterized in that, The indication information is the sector PN that uniquely identifies the sector. 13. The soft handover resource assignment system according to claim 10, wherein the indication information is an active set index that uniquely identifies a sector in the active set. 14. The soft handover resource assignment system according to claim 10, wherein the indication information is a bitmap field, and each sector corresponds to one bit. 15. The soft handover resource assignment system according to claim 14, wherein when the bitmap field is 1, it indicates that the corresponding sector is in the set of sectors, when the bitmap When the field is 0, it means that the corresponding sector is not in the sector set. 16. The soft handover resource assignment system according to claim 10, wherein the data transmission module receives downlink data or sends uplink data according to the channel resource allocation information in the soft handover resource assignment message . 17. The soft handover resource assignment system according to claim 14 or 16, wherein when the data transmission module sends uplink data, the soft handover resource assignment message does not include the bitmap field.

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