WO2010075642A1

WO2010075642A1 - Method for handover cancelling

Info

Publication number: WO2010075642A1
Application number: PCT/CN2008/002156
Authority: WO
Inventors: 刘锟; 鲁照华; 刘颖
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-12-31
Filing date: 2008-12-31
Publication date: 2010-07-08

Abstract

A method for handover cancelling, which includes the following steps: a service BS(Base Station) allocates different TF(Time-Frequency) resource blocks for different terminals, which are in handover state or prepare to handover; the terminal, which performs the handover cancelling, sends the handover cancel signaling in the TF resource block allocated by the service BS. The service BS performs decoding for the TF resource block allocated for the terminals, acquires the terminal which sends the handover cancel request according to the relationship between the TF recourse block and the terminal, and sends handover cancel response signal to the terminal which has sent the handover cancel signaling. The method for handover cancelling in the present invention can reduce the period and complexity of terminal handover cancelling, and improve system operation efficiency effectively.

Description

Switch cancellation method

Technical field

The present invention relates to the field of communications, and in particular, to a handover cancellation method.

Background technique

In a wireless communication system, a base station (BS) refers to a device that provides services for a mobile station (MS). The base station communicates with the terminal through uplink and downlink channels. The downlink channel is a channel through which the base station transmits data to the terminal, and the uplink channel is a channel through which the terminal transmits data to the base station. Multiple terminals can simultaneously transmit data to the base station through the uplink channel, or can receive data from the base station through the downlink channel at the same time.

The terminal may move from the air interface (Air Interface) of one base station (called the service base station) to another base station due to signal fading, interference, or higher quality of service (QoS). For the air interface of the target base station, this process is a handover.

During the process of switching, the switching operation is usually cancelled at any time for some reason. The flow of the handover cancellation processing in the existing IEEE ( Institute of Electrical and Electronics Engineers) 802.16e system is as shown in FIG. 1 , and specifically includes the following steps:

101: In the handover preparation phase, the terminal entering the handover state (hereinafter referred to as the terminal) performs information interaction with the service base station, and the serving base station notifies the target base station of necessary information related to the terminal entering the handover state.

102: The terminal sends a notification message to the serving base station that it determines to switch to the target base station.

103: When the terminal needs to cancel the handover for some reason, the terminal sends a time-frequency resource request signaling based on the contention mode to the serving base station.

104: The serving base station responds to the time-frequency resource request of the terminal, and includes, in the response signaling, result information of whether to allocate time-frequency resources for the terminal.

105: After receiving the response signaling of the serving base station, if the terminal includes the result information The serving base station prepares to allocate time-frequency resources to it, and then applies to the serving base station for time-frequency resources for transmitting handover cancellation signaling.

106: The base station allocates time-frequency resources to the terminal, and sends corresponding time-frequency resource information (for example, a slot number and a sub-carrier number) to the terminal.

107: The terminal sends a handover cancellation signaling to the allocated time-frequency resource by the serving base station.

It can be seen from the foregoing process that, in the handover process of the prior art, the terminal needs to apply for time-frequency resources for transmitting handover cancellation signaling in a competitive manner, which increases the cycle and complexity of the handover cancellation operation, and reduces The system operates efficiently. Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and to provide a handover canceling method that can effectively shorten the period of the handover cancel operation and reduce the complexity of the handover cancel operation.

In order to solve the above problem, the present invention provides a handover cancellation method, the method comprising: the serving base station separately assigning different time-frequency resource blocks to each terminal in a handover state or preparing to handover;

The terminal performing the handover cancel operation transmits switching cancellation signaling to the time-frequency resource block allocated by the serving base station.

In addition, the serving base station decodes the time-frequency resource block allocated to each of the terminals, and learns the terminal that sends the handover cancellation signaling according to the correspondence between the time-frequency resource block and the terminal, and sends the handover to the terminal that has sent the handover cancellation signaling. Cancel response signaling.

In addition, if the terminal that has sent the handover cancellation signaling receives the handover cancellation response signaling sent by the serving base station in a preset time interval after transmitting the handover cancellation signaling, the terminal completes the subsequent handover cancellation operation. Otherwise, the terminal again uses the serving base station to send handover cancellation signaling or perform re-access to the network for the time-frequency resource block allocated thereto.

In addition, the handover cancellation response signaling is sent by the serving base station to the terminal through a downlink channel, where the handover cancellation response signaling includes: an index number of a time-frequency resource block allocated to the terminal, and/or an index number of the terminal. And/or indicate the indication that the switch cancel operation is confirmed. The invention also provides a handover cancellation method, the method comprising:

The serving base station allocates a time-frequency resource block TF ₁ for the terminals in the handover state or ready to handover, and respectively allocates mutually orthogonal or quasi-orthogonal codeword sequences for indicating the handover cancel operation for the 128⁄4 terminals;

And performing, by the terminal, the handover cancellation operation, the terminal that obtains the codeword sequence allocated by the serving base station, and generating handover cancellation signaling according to the codeword sequence, and sending the time-frequency resource block to the serving base station;

Wherein, 13⁄4 is an integer greater than 1, and i=l, I, I is an integer greater than or equal to 1.

Further, if a = 1, the serving base station when decoding frequency resource blocks TF _l learned terminal sends a handover cancellation signaling codeword sequence according to a correspondence relationship with the terminal, sent to the terminal sends a handover signaling handover cancel to cancel response signal make.

Further, if a> 1, the serving base station decodes each of the time-frequency resource block is known TF ₁ and the terminal sends a handover cancellation signaling and resource blocks according to a correspondence relationship with the terminal when the code word sequence frequency, to cancel the handover signaling has been sent The terminal sends a handover cancellation response signaling.

In addition, after the serving base station allocates the codeword sequence to the terminal, the index of the codeword sequence in the codeword sequence set is sent to the terminal;

The terminal performing the handover cancel operation in the 144 terminals acquires a codeword sequence allocated by the serving base station for the serving base station in the codeword sequence set according to the index.

In addition, the serving base station allocates time-frequency resource blocks TF _I+1 TF _{I+N for the N} terminals in the handover state or ready to handover, respectively;

And transmitting, by the serving base station, the handover cancellation signaling to the time-frequency resource block allocated by the serving base station;

The serving base station decodes the time-frequency resource block TF _I+1 TF _I+N , and learns the terminal that sends the handover cancellation signaling according to the correspondence between the time-frequency resource block and the terminal, and sends a handover cancellation response to the terminal that has sent the handover cancellation signaling. Signaling

Where N is an integer greater than or equal to 1. In addition, if the terminal that has sent the handover cancellation signaling receives the handover cancellation response signaling sent by the serving base station in a preset time interval after transmitting the handover cancellation signaling, the terminal completes the subsequent handover cancellation operation. Otherwise, the terminal again uses the serving base station to send handover cancellation signaling or perform re-access to the network for the time-frequency resource block allocated thereto.

In addition, the handover cancellation response signaling is sent by the serving base station to the terminal through a downlink channel, where the handover cancellation response signaling includes: a time-frequency resource block index number allocated to the terminal, and/or an index number of the terminal, And/or an index number of a codeword sequence assigned to the terminal, and/or indication information indicating that the handover cancel operation is confirmed.

Furthermore, the handover cancellation signaling is signaling of the codeword sequence itself or by spreading the pre-set information with the codeword sequence as a spreading code.

The handover cancellation method of the present invention can be used in the IEEE 802.16e system, which shortens the cycle of the handover cancellation operation of the terminal in the IEEE 802.16e system, reduces the complexity of the handover cancellation operation, and effectively improves the operation efficiency of the system. BRIEF abstract

FIG. 1 is a flowchart of performing handover cancellation processing in an IEEE 802.16e system;

2 is a flowchart of a handover canceling method according to a first embodiment of the present invention;

3 is a schematic diagram of a location relationship between a base station and a terminal in the first and second embodiments of the present invention; FIG. 4 is a schematic diagram of a dedicated time-frequency resource block allocated by a serving base station to a terminal according to the first embodiment of the present invention;

FIG. 5 is a flowchart of a handover canceling method according to a second embodiment of the present invention; FIG.

6 is a flowchart of a method for canceling a handover according to a third embodiment of the present invention;

7 is a schematic diagram showing a positional relationship between a base station and a terminal according to a third embodiment of the present invention;

FIG. 8 is a schematic diagram of multiple shared time-frequency resource blocks allocated by a serving base station to a terminal according to a third embodiment of the present invention. Preferred embodiment of the invention

The basic idea of the present invention is that the serving base station allocates dedicated time domain-frequency domain resources (referred to as time-frequency resources) for transmitting handover cancellation signaling to each terminal in the handover state, or allocates terminals for entering the handover state. After transmitting the codeword sequence of the handover cancellation signaling and the shared time-frequency resource, the terminal sends the handover cancellation signaling by using the time-frequency resource or the time-frequency resource and the codeword sequence when the handover needs to be cancelled.

The invention will now be described in detail in conjunction with the drawings and embodiments. First Embodiment: FIG. 2 is a flowchart of a handover canceling method according to a first embodiment of the present invention. In this embodiment, the terminals MS1 and MS2 are in a handover state, and are ready to be handed over from the serving base station BS1 to the target base station BS2, and the positional relationship between each base station and the terminal is as shown in FIG.

As shown in FIG. 2, the handover cancellation method of the first embodiment of the present invention specifically includes the following steps: Step 201: In the handover preparation phase, the serving base station BS1 is respectively a terminal in a handover state.

MS1 and MS2 allocate a dedicated time-frequency resource block (TF) and transmit the allocated time-frequency resource block information to the corresponding terminal.

The terminal may send handover cancellation signaling using the dedicated time-frequency resource block described above.

As shown in FIG. 4, the serving base station BS1 allocates a dedicated time-frequency resource block TF1 to the terminal MS1 and allocates a dedicated time-frequency resource block TF2 to the terminal MS2.

Step 202: The terminal sends handover cancellation signaling to the dedicated time-frequency resource block allocated by the serving base station BS1 according to the received time-frequency resource block information.

In this embodiment, it is assumed that the terminal MS2 needs to perform a handover cancel operation, and the terminal MS2 transmits handover cancellation signaling on the dedicated time-frequency resource block TF2 allocated by the serving base station BS1.

For example, according to the setting of the system, the data "01" indicates that the terminal requests to cancel the handover, and the above handover cancellation signaling is the data "01" sent by the MS2 on the time-frequency resource block TF2.

Step 203: The serving base station BS1 decodes the dedicated time-frequency resource blocks TF1 and TF2, and finds the TF2. The transmitted data is "01". Therefore, according to the correspondence between the time-frequency resource block and the terminal, it is learned that the terminal MS2 requests to perform the handover cancel operation.

Step 204: The serving base station BS1 sends the handover cancellation response signaling by using a downlink channel in a unicast, multicast, or broadcast manner.

The format of the above handover cancellation response signaling is: an index number of the terminal + an indication information for confirming the handover cancellation operation.

Assuming that the index number of the terminal MS2 is "01", the indication information for confirming the handover cancel operation is indicated by one bit "1", and the above-mentioned handover cancellation response signaling is: "011".

Step 205: If the MS2 receives the transmission handover cancellation response signaling sent by the serving base station BS1 within a preset time length (for example, 20 ms), the handover cancellation operation is completed; otherwise, the MS 2 performs after the preset time length. Step 202, or perform an operation of re-accessing the network. Second Embodiment FIG. 5 is a flowchart of a handover canceling method according to a second embodiment of the present invention. In this embodiment, the terminals MS1 and MS2 are in a handover state, and are ready to be handed over from the serving base station BS1 to the target base station BS2, and the positional relationship between each base station and the terminal is as shown in FIG.

As shown in FIG. 5, the handover cancellation method of the second embodiment of the present invention specifically includes the following steps: Step 501: In the handover preparation phase, the serving base station BS1 allocates a shared time-frequency resource block to the terminals MS1 and MS2 in the handover state, and respectively The terminal MS1 and the MS2 are allocated mutually orthogonal or quasi-orthogonal codeword sequences; the serving base station BS1 transmits the information of the shared time-frequency resource block and the codeword sequence allocated for the terminal to the corresponding terminal.

The above codeword sequence can be used to indicate a handover cancel operation.

The information of the above codeword sequence may be a codeword index number in a set of codeword sequences.

The above codeword sequence may be a walsh code (an orthogonal code).

For example, the serving base station BS1 allocates a codeword sequence A1 in the walsh codeword sequence set for the terminal MS1 to indicate a handover cancel operation, and the corresponding index number is al, and allocates a codeword sequence to the terminal MS2. A2 is used to indicate the switch cancel operation, and the corresponding index number is a2; A1 and A2 are orthogonal to each other.

Step 502: The terminal sends the handover cancellation signaling on the shared time-frequency resource block by using the codeword sequence allocated by the serving base station BS1.

The terminal may obtain a corresponding codeword sequence from the codeword sequence set according to the codeword sequence index number sent by the serving base station BS1.

In this embodiment, it is assumed that both the terminal MS1 and the MS2 need to perform the handover cancel operation, and the MS1 transmits the codeword sequence A1 on the shared time-frequency resource block allocated by the serving base station BS1, and the MS2 transmits the codeword sequence A2 on the shared time-frequency resource block. That is, the terminal MS1 uses the codeword sequence A1 as the handover cancellation signaling, and the terminal MS2 uses the codeword sequence A2 as the handover cancellation signaling.

Step 503: The serving base station BS1 decodes the shared resource block, and according to the correspondence between the codeword sequence and the terminal, it is learned that both the terminals MS1 and MS2 are required to perform the handover cancel operation.

Step 504: The serving base station BS1 sends the handover cancellation response signaling by using a downlink channel in a unicast, multicast, or broadcast manner.

Similarly, the format of the handover cancellation response signaling is: terminal index number + indication information for confirming the handover cancellation operation.

4, the index number of the terminal MS1 is "00", the index number of the terminal MS2 is "01", the indication information of the handover cancellation response is indicated by one bit "1", and the handover cancellation response signaling for the terminal MS1 is: "001 " , the handover cancellation response signaling for the terminal MS2 is: "011".

Step 505: If the terminal MS1 and the MS2 receive the transmission handover cancellation response signaling sent by the serving base station BS1 within a preset time length (for example, 20 ms), the handover cancellation operation is completed; otherwise, the handover cancellation response signaling is not received. The terminal performs step 502 after the preset length of time, or performs an operation of re-accessing the network. Third Embodiment FIG. 6 is a flowchart of a handover canceling method according to a third embodiment of the present invention. In this embodiment, the terminal MS1 is

MS2, MS3, and MS4 are in a handover state, ready to be handed over from the serving base station BS1 to the target base station BS2, and the positional relationship between each base station and the terminal is as shown in FIG. As shown in FIG. 6, the handover cancellation method of the third embodiment of the present invention specifically includes the following steps: Step 601: In the handover preparation phase, the serving base station BS1 allocates multiple shared time-frequency resource blocks for the terminal in the handover state, and uses The terminal of the same shared time-frequency resource block allocates mutually orthogonal or quasi-orthogonal codeword sequences; the serving base station BS1 transmits the information of the shared time-frequency resource block and the codeword sequence allocated for the terminal to the corresponding terminal.

As shown in FIG. 8, in the embodiment, the serving base station BS1 allocates two shared time-frequency resource blocks TF1 and TF2, wherein the shared time-frequency resource block TF1 is allocated to the terminals MS1 and MS2, and the shared time-frequency resource block TF2 is allocated to Terminals MS3 and MS4.

Similarly, the above codeword sequence may be used to indicate a handover cancel operation, and the information of the codeword sequence may be a codeword index number in a codeword sequence set; the codeword sequence may be a walsh code.

For example, in the embodiment, the serving base station BS1 allocates a codeword sequence A1 in the walsh codeword sequence set for the terminal MS1 to indicate a handover cancel operation, and the corresponding index number is al, and allocates a codeword sequence A2 to the terminal MS2 for indicating handover. For the cancel operation, the corresponding index number is a2, and the codeword sequence A3 in the walsh codeword sequence set is allocated to the terminal MS3 for indicating the handover cancel operation, the corresponding index number is a3, and the terminal MS4 is assigned the codeword sequence A4 for indicating Switch cancel operation, the corresponding index number is a4.

Step 602: The terminal sends the handover cancellation signaling on the corresponding shared time-frequency resource block by using the codeword sequence allocated by the serving base station BS1.

In this embodiment, it is assumed that the terminals MS1, MS2, MS3, and MS4 need to perform the handover cancellation operation to transmit the codeword sequence A2 on the time-frequency resource block TF1, and the terminal MS3 is on the shared time-frequency resource block TF2, that is, the terminal MS1 will sequence the codeword. A1 is used as handover cancellation signaling, the terminal MS2 uses the codeword sequence A2 as handover cancellation signaling, the terminal MS3 uses the codeword sequence A3 as handover cancellation signaling, and the terminal MS4 uses the codeword sequence A4 as handover cancellation signaling.

Step 603: The serving base station BS1 decodes the shared resource blocks TF1 and TF2 according to the time-frequency resource block. And the corresponding relationship between the codeword sequence and the terminal, it is learned that the terminals MS1, MS2, MS3, and MS4 all require the handover cancel operation to be performed.

Step 604: The serving base station BS1 sends the handover cancellation response signaling by using a downlink channel in a unicast, multicast, or broadcast manner.

4, the index number of the terminal MS1 is "00", the index number of the terminal MS2 is "01", the index number of the terminal MS3 is "10", and the index number of the terminal MS4 is "11", represented by a bit "1" The handover cancel response indication information is: the handover cancellation response signaling for the terminal MS1 is: "001", the handover cancellation response signaling for the terminal MS2 is: "011", and the handover cancellation response signaling for the terminal MS3 is: "101 " , the handover cancellation response signaling for the terminal MS2 is: "111".

Step 605: If the terminals MS1, MS2, MS3, and MS4 receive the transmission handover cancellation response signaling sent by the serving base station BS1 within a preset time length (for example, 20 ms), the handover cancel operation is completed; otherwise, the handover cancellation is not received. The terminal responding to the signaling performs step 602 after the predetermined length of time, or performs an operation of re-accessing the network.

According to the basic principle of the present invention, the above embodiment has various transformations, such as:

For example, in the third embodiment, the terminal MS3 may also be assigned a codeword sequence A1 in the walsh codeword sequence set, and the terminal MS4 may be assigned a codeword sequence A2.

(2) The serving base station may allocate a shared time-frequency resource block for some terminals and allocate a dedicated time-frequency resource block for another part of the terminal. Combining the shared time-frequency resource block with the dedicated time-frequency resource block avoids the case where a time-frequency resource block is allocated to a single terminal and a codeword sequence is assigned to it.

For example, the walsh codeword sequence set includes three available codeword sequences: Al, A2, and A3, and currently four terminals are in a handover state: terminals MS1, MS2, MS3, and MS4, then the serving base station may be the terminals MS1, MS2. MS3 allocates a shared time-frequency resource block TF1 and assigns a codeword sequence Columns A1, A2, and A3; simultaneously allocate a dedicated time-frequency resource block TF2 to the terminal MS4.

When the serving base station uses the shared time-frequency resource block and the dedicated time-frequency resource block at the same time, the terminal may allocate a codeword sequence to the serving base station (ie, whether to send the codeword sequence index to the terminal). Or the method of the second embodiment transmits handover cancellation signaling.

(3) For the first embodiment, the handover cancellation response signaling may include only the index number of the time-frequency resource block allocated to the terminal or the index number of the terminal; in addition, if the serving base station transmits the handover to the corresponding terminal by using the unicast mode If the response signaling is canceled, the indication information of the handover cancellation response signal may include only the confirmation handover cancellation operation.

For the second embodiment, the handover cancellation response signaling may include only the index number of the codeword sequence assigned to the terminal.

For the second embodiment and the third embodiment, the handover cancellation response signaling may only include the index number of the terminal; in addition, if the serving base station sends the handover cancellation response signaling to the corresponding terminal by using the unicast mode, the handover cancellation response signal is switched. The command may include only the index number of the codeword sequence allocated for the terminal, or the time-frequency resource block index number assigned to the terminal.

(4) For the second embodiment and the third embodiment, the handover cancellation signaling sent by the terminal may be that the codeword sequence allocated by the serving base station is a spreading code, and the extension obtained after spreading the preset information is obtained. Frequency code subsequence. For example, the "01" bit is used to indicate the handover cancel operation, and the code subsequence allocated by the terminal MS1 is "-1, -1, 1, 1", and the spreading sequence obtained after the spreading is "1, 1, -1, -1" "-1-111", the handover cancellation signaling sent by the terminal MS1 is "11-1-1-1-111".

Industrial applicability

The handover cancellation method of the present invention can be used in the IEEE 802.16e system, which shortens the cycle of the handover cancellation operation of the terminal in the IEEE 802.16e system, reduces the complexity of the handover cancellation operation, and effectively improves the operation efficiency of the system.

Claims

Claim

A handover cancellation method, characterized in that the method comprises:

The serving base station allocates different time-frequency resource blocks for each terminal that is in a handover state or is ready to switch.

2. The method of claim 1 wherein:

The serving base station decodes the time-frequency resource block allocated to each terminal, and learns a terminal that sends handover cancellation signaling according to the correspondence between the time-frequency resource block and the terminal, and sends a handover cancellation response to the terminal that has sent the handover cancellation signaling. Signaling.

3. The method of claim 2, wherein

If the terminal that has sent the handover cancellation signaling receives the handover cancellation response signaling sent by the serving base station within a preset time interval after transmitting the handover cancellation signaling, the terminal completes the subsequent handover cancellation operation; otherwise, The terminal again uses the serving base station to send handover cancellation signaling or perform re-access to the network for the time-frequency resource block allocated thereto.

4. The method of claim 2 or 3, wherein

The handover cancellation response signaling is sent by the serving base station to the terminal through a downlink channel. The handover cancellation response signaling includes: an index number of a time-frequency resource block allocated to the terminal, and/or an index number of the terminal, and / or indicate the instruction to confirm the switch cancel operation.

5. A handover canceling method, characterized in that the method comprises:

The terminal performing the handover cancel operation in the 128⁄4 terminals acquires a codeword sequence allocated by the serving base station, and generates handover cancellation signaling according to the codeword sequence, and sends the handover to the time-frequency resource block. Serving base station;

6. The method of claim 5, wherein

If 1 = 1, the serving base station decodes the frequency resource blocks TF _l known switching transmission codeword sequence according to a correspondence relationship with the terminal end of the cancellation signaling sent to the switching terminal sends a handover Cancel Cancel signaling response signaling.

7. The method of claim 5, wherein

If a> 1, the serving base station decodes each of the time-frequency resource block is known TF ₁ and the terminal sends a handover cancellation signaling and resource blocks according to a correspondence relationship with the terminal when the code word sequence frequency, to the transmitting terminal has been switched signaling Cancel Send handover cancellation response signaling.

8. The method of claim 5, wherein

After the serving base station allocates the codeword sequence to the terminal, the index of the codeword sequence in the codeword sequence set is sent to the terminal;

9. The method of claim 5, wherein

The serving base station allocates time-frequency resource blocks TFi+i, ..., TFi _{+N for the N} terminals that are in the switching state or are ready to switch.

Where N is an integer greater than or equal to 1.

10. A method as claimed in claim 6 or 7 or 9, characterized in that If the terminal that has sent the handover cancellation signaling receives the handover cancellation response signaling sent by the serving base station within a preset time interval after transmitting the handover cancellation signaling, the terminal completes the subsequent handover cancellation operation; otherwise, The terminal again uses the serving base station to send handover cancellation signaling or perform re-access to the network for the time-frequency resource block allocated thereto.

11. The method of claim 6 or 7 or 9, wherein

The handover cancellation response signaling is sent by the serving base station to the terminal through the downlink channel; the handover cancellation response signaling includes: a time-frequency resource block index number allocated to the terminal, and/or an index number of the terminal, and/or Or an index number of a codeword sequence assigned to the terminal, and/or an indication message indicating that the handover cancel operation is confirmed.

12. The method of claim 5, wherein

The handover cancellation signaling is signaling of the codeword sequence itself or by spreading the pre-set information with the codeword sequence as a spreading code.