CN1985526B - Method and apparatus for processing data blocks during soft handover - Google Patents

Abstract

A method and device for processing data blocks during soft handover. The device can be a wireless communication system, including at least two enhanced uplink soft handover nodes B and a radio network controller. Each Node B can decode received data blocks and forward the decoded data blocks to the RNC. If the RNC receives at least one copy of the successfully decoded data block, the RNC may use the reordering function entity to successfully process the copy of the decoded data block to support in-queue delivery to a higher protocol layer. If the RNC receives more than one copy of the successfully decoded data block, the RNC discards the additional copies of the successfully decoded data block. The wireless network controller is a serving wireless network controller or a controlling wireless network controller. Each Node B includes a MAC entity that can handle the enhanced UL dedicated channel function.

Description

Method and device for processing data blocks during soft handover

technical field

The present invention relates to the field of wireless communication. More particularly, the present invention relates to processing data blocks in multi-cell wireless communication systems such as Frequency Division Duplex (FDD) or Time Division Duplex (TDD).

Background technique

Methods to improve uplink coverage, throughput and transmission delay are currently being examined by the 3rd Generation Partnership Project (3GPP) in the context of Release 6 (R6) Universal Mobile Telecommunications System (UMTS) research project "Frequency Division Duplex Uplink Enhancement" middle.

To achieve these goals, it is widely expected that Node Bs (base stations) will assume responsibility for scheduling and allocating uplink resources (actual channels) to users. The principle is that even if the RNC maintains rough control, the Node B can make more effective decisions and manage uplink radio resources than the RNC on a short-term basis. A similar approach has been adopted in Release 5 (R5) High Speed Downlink Packet Access (HSDPA) in Universal Mobile Telecommunications System Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes.

It is also contemplated that several independent uplinks are processed between the WTRU and the UTRAN within a shared time segment. An example of this is MAC layer hybrid automatic repeat request (HARQ) or MAC layer automatic repeat request (ARQ) only operation, where each transmission may require a different number of transmissions to be successfully received by the UTAN. In order to limit the impact on the system architecture, it is expected that the protocol layer on the MAC should not be affected by the introduction of the Enhanced Uplink Dedicated Channel (EU-DCH). One requirement introduced by this is the in-queue data passed to the Radio Link Control (RLC) protocol layer. Therefore, similar to the high-speed downlink packet access operation in the downlink, the ULAR reordering function is required to organize the received data blocks according to the queue generated by the RLC entity of the WTRU.

The soft handover macro-diversity operation system needs to centrally control the uplink transmission in each cell in the active group. An active group may contain multiple Node Bs. Retransmissions are generated until at least one Node B achieves a successful transmission. Successful transmission is not guaranteed by all Node Bs. Therefore, the reordering of successful transmissions cannot be completed because a successful transmission completion set may not be available in any of the Node Bs.

Contents of the invention

The invention relates to a method and device for processing data blocks during soft handover. The device can be a wireless communication system, a radio network controller (RNC) or an integrated circuit (IC). The wireless communication system includes at least two enhanced uplink soft handover nodes B and a radio network controller. Each Node B can decode a received data block and forward the decoded data block with a decoding result, ie, a cyclic redundancy check (CRC), to the radio network controller. If the RNC receives at least one copy of a successfully decoded data block, the RNC may use the reordering function to successfully process the decoded data block to provide in-queue delivery to a higher protocol layer. If the RNC receives more than one copy of the successfully decoded data block, the RNC discards the additional copies of the successfully decoded data block. The radio network controller is a serving radio network controller (S-RNC) or a controlling radio network controller (C-RNC). Each Node B includes a MAC entity that can handle the enhanced UL dedicated channel function.

Description of drawings

FIG. 1 is a block diagram of a wireless communication system for processing data blocks in a serving wireless network controller according to a preferred embodiment of the present invention.

FIG. 2 is a process flow diagram including method steps for processing data blocks in the system of FIG. 1 .

FIG. 3 is a block diagram of a wireless communication system for processing and controlling data blocks in a wireless network controller according to an alternative embodiment of the present invention.

FIG. 4 is a process flow diagram including method steps for processing data blocks in the system of FIG. 3 .

Detailed ways

The present invention will be described with reference to the drawings, wherein like reference numerals refer to like components throughout.

Hereinafter, the term "WTRU" includes, but is not limited to, user equipment (UE), mobile station, fixed or mobile subscriber unit, pager or any other type of device operable in a wireless environment. The term "base station" hereafter is intended to include, but not be limited to, a Node B, address controller, access point, or other type of interfacing device in a wireless environment.

As generally applied to universal mobile telecommunication systems, CDMA2000 (code division multiple access 2000) and code division multiple access, the present invention can be further applied to time-division duplex, frequency-division duplex and time-division synchronous code-division multiple access (TD-SCDMA), but application to other wireless systems is also envisioned. For CDMA2000, the invention can be implemented in EV-DO (ie, data only) and EV-DV (ie, data and voice).

During the soft handover operation, higher layers maintain the active subset of UL cells, for which the UL dedicated channel is maintained in the soft handover macro-diversity state. Cells in these active subsets are controlled by different enhanced uplink soft handover Node Bs.

1 shows a wireless communication system 100 comprising a serving radio network controller 105 and at least two (2) enhanced uplink soft handover nodes B 110 (110A...110N) operating in accordance with a preferred embodiment of the present invention. With or without soft handover, each WTRU has one or more reordering functions 115 implemented in the serving RNC 105 . The HARQ or ARQ processing for processing the EUL-DCH function is placed in the MAC entity 120 in each EUL soft handover node B 110. Each reordering functional entity 115 can communicate with a higher protocol layer 125 within the serving RNC 105 and includes an associated data buffer (unnumbered).

2 is a flowchart of a process 200 that includes method steps for processing data blocks, ie, packet data units (PDUs), in system 100 during a soft handover. In step 205, the data block, (ie the EU data block) is received from the WTRU at each EU soft handover node B 110. In step 210, each enhanced uplink soft handover node B 110 decodes the received data block, and the decoded data block is forwarded to the serving radio network controller 105. It should be noted that each EU soft handover Node B 110 will attempt to decode received EU transmissions. When with periodic redundancy checks, each enhanced uplink soft handover node B 110 cannot forward a received data block to Serving radio network controller 105 . All successfully decoded blocks with good CRC results are forwarded to the serving RNC 105 .

Still referring to FIG. 2 , it is determined whether at least one copy of the successfully decoded data block is received by the serving radio network controller 105 from the enhanced uplink soft handover node B 110 (step 215 ). If it is determined in step 215 that the serving RNC 105 has not received any copy of the successfully decoded data block, then the forwarded data block is deemed not to have been correctly received (step 220 ). In step 215, if it is determined that at least one copy of the successfully decoded data block is received from the enhanced uplink soft handover node B 110 by the serving radio network controller 105, then it is determined whether multiple copies of the successfully decoded data block are received from different enhanced The uplink soft handover Node B 110 is received (step 225).

If step 225 determines that multiple copies of the successfully decoded data block are received from different EUP soft handover Node Bs 110, only one copy is stored in the reordering functional entity 115 maintained in the serving radio network controller 105 Data blocks in the reordering buffer (not shown) are treated as correctly received, and any additional received copies of successfully decoded data blocks are discarded as redundant data (step 230).

Finally, in step 235 , the successfully decoded data block is processed by the reordering function entity 115 in the serving radio network controller 105 . The reordering function 115 in the serving radio network controller 105 can perform a reordering process on these successfully decoded data blocks that are correctly received in the reordering function 115 to support the transfer to the higher protocol layer 125 .

Process 200 is beneficial because data blocks received from different UL soft handover Node-Bs 110 can be combined and organized in a queue for delivery to the higher protocol layer 125 of the serving RNC 105. The reordering functional entity 115 placed in the serving radio network controller 105 enables the EU MAC PDUs to be processed independently of the Node B provided to receive each PDU for successful reception and correct delivery to the higher High protocol layer 235, causing MAC data to be dropped and RLC to resume.

3 shows a wireless communication system 300 comprising a controlling radio network controller 305 and at least two (2) enhanced uplink soft handover Node Bs 110 (110A...110N) operating in accordance with an alternative embodiment of the present invention. One or more reordering functional entities 315 are implemented to control the radio network controller 305 to support soft handover. The HARQ or ARQ processing for handling the EUL-DCH function is placed in the MAC entity 320 in each EUL soft handover node B 310. Each reordering functional entity 315 can communicate with a higher protocol layer 325 externally connected to the control radio network controller 305 and includes an associated data buffer (no number).

FIG. 4 is a flowchart of a process 400 that includes method steps for data blocks, ie, PDUs, in the processing system 300 during soft handover. In step 405, the data block, (ie, the EU data block) is received from the WTRU at each EU soft handover node B 310. In step 410, each EU soft handover node B 310 decodes the received data block, and the decoded data block is forwarded to the controlling radio network controller 305. It should be noted that each EU soft handover Node B 310 will attempt to decode received EU transmissions. When with periodic redundancy checks, each enhanced uplink soft handover node B 310 cannot forward a received data block to Controls the wireless network controller 305 . All successfully decoded blocks with good CRC results are forwarded to the controlling radio network controller 305 .

Still referring to FIG. 4 , it is determined whether at least one copy of the successfully decoded data block is received by the controlling radio network controller 305 from the enhanced uplink soft handover node B 310 (step 415 ). If it is determined in step 415 that the control radio network controller 305 has not received any copy of the successfully decoded data block, then the data block forwarded by the enhanced uplink soft handover node B 310 is deemed not to have been correctly received (step 420) . In step 415, if it is determined that at least one copy of the successfully decoded data block is received from the enhanced uplink soft handover node B 310 by the controlling radio network controller 305, then it is determined whether multiple copies of the successfully decoded data block are received from different enhanced uplink A chain soft handover Node B 310 is received (step 425).

If step 425 determines that multiple copies of the successfully decoded data block are received from different enhanced uplink soft handover Node Bs 310, only one copy is stored in the reordering function entity 315 maintained in the controlled radio network controller 305 The data blocks in the reordering buffer (unlabeled) are treated as correctly received, and any additional received copies of successfully decoded data blocks are discarded as redundant data (step 430).

Finally, in step 435 , the successfully decoded data block is processed by the reordering function entity 315 in the controlling radio network controller 305 . It can perform a reordering procedure on these successfully decoded data blocks that are correctly received in the reordering function 315 to support the transfer to the higher protocol layer 325 .

Process 400 is beneficial because data blocks received from different UL Soft Handover Node Bs 310 can be combined and organized in queues for delivery, assuming the Nodes B 310 have the same controlling RNC 305 to higher protocol layers 325 . Although its application is somewhat stricter than placing the reordering function in the serving RNC 105, this is often the case. However, this limitation is offset by other considerations. For example, it is of interest to the operation of the serving radio network controller to reduce the latency of hybrid auto-repeat request operations. The performance benefits of minimizing this delay are well known in the art. During soft handover, it is also contemplated that the controlling RNC 305 has a shared UL scheduler in the RNC 305 for all cells in the EUL subset containing cells controlled by a different Node B 310.

Although the present invention has been particularly shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention as described above.

Claims (8)

1. A method for processing data blocks during soft handover for use in a radio network controller (RNC), wherein the radio network controller (RNC) comprises a reordering functional entity, the method comprising: receiving at least one copy of the decoded data block; On condition that more than one decoded copy of the data block is received, discarding additional decoded copies of the data block; and In response to receiving at least one copy of the decoded data block, using the reordering functionality to reorder copies of the decoded data block that were not discarded to support Passed to the higher protocol layer by queue on the uplink (EU) channel. 2. The method of claim 1, wherein the radio network controller is a serving radio network controller (S-RNC), and the higher protocol layer is located within the serving radio network controller. 3. The method of claim 1, wherein the radio network controller is a controlling radio network controller (C-RNC), and the higher protocol layer is external to the controlling radio network controller. 4. A radio network controller (RNC) for processing data blocks during soft handover, the radio network controller being configured to receive at least one copy of the decoded data blocks and to discard received additional successful A copy of the decoded data block, the RNC contains: At least one reordering functional entity for reordering non-discarded copies of decoded data blocks to support queued delivery to higher protocol layers on one or more Enhanced Uplink (EU) channels. 5. The radio network controller of claim 4, wherein the radio network controller is a Serving Radio Network Controller (S-RNC). 6. The radio network controller of claim 4, wherein the radio network controller is a controlling radio network controller (C-RNC). 7. An integrated circuit (IC) for processing data blocks during soft handover, the integrated circuit configured to receive at least one copy of a decoded data block and to discard received additional successfully decoded data blocks A copy of the block, the IC contains: At least one reordering functional entity for reordering non-discarded copies of decoded data blocks to support queued delivery to higher protocol layers on one or more Enhanced Uplink (EU) channels. 8. The integrated circuit of claim 7, wherein the integrated circuit is located in a Serving Radio Network Controller (S-RNC) that handles forwarding to the Serving Radio Network Controller during soft handover data block.

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