KR20010072259A - Group addressing in a packet communication system - Google Patents

Abstract

The wireless communication system supports forward error correction (FEC) / automatic repeat (ARQ) techniques to process erroneously received data blocks. The transmission of sequence numbers associated with each data block is independent of the data block itself, which in turn reduces latency and improves memory usage efficiency. By separating the transmission of payload data from the block and sub-block identifiers, a more robust variable redundancy technique is created. For example, a group of block sequence numbers may be transmitted together as a bitmap, thereby eliminating the need to specify the individual sequence number completely. Instead, the starting sequence number can be fully specified, and the other sequence numbers are represented by an increment or a subsequent offset from the starting sequence number.

Description

[0001] GROUP ADDRESSING IN A PACKET COMMUNICATION SYSTEM [0002]

With the growth of commercial communication systems, and especially the explosive growth of cellular wireless telephone systems, system designers have sought ways to increase system capacity without compromising communication quality to the extent that consumers are allowed to. One way to achieve this goal involves a technique of changing from a system where analog modulation is used to place data on a carrier wave to a system where digital modulation is used to load data onto a carrier wave.

In a wireless digital communication system, most of the system parameters, including modulation type, burst format, communication protocol, etc., are specified by standardized air interfaces. For example, the European Telecommunication Standard Institute (ETSI) specifies the Global System for Mobile Communications (GSM) standard, which specifies a Gaussian minimum at a symbol rate of 271 ksps Time-division multiple access that transmits and receives control, voice, and information over physical radio frequency (RF) channels or links using Gaussian Minimum Shift Keying (GMSK) modulation techniques. In the United States, the Telecommunication Industry Association (TIA) publishes a number of interim standards, such as IS-54 and IS-136, which use differential quadrature phase shift keying defines various versions of digital advanced mobile phone service (D-AMPS), a TDMA system using differential quadrature phase shift keying (DQPSK) modulation techniques.

A TDMA system divides an available frequency into one or more RF channels. The RF channels are further divided into a plurality of physical channels corresponding to time slots in a TDMA frame. A logical channel is composed of one or several physical channels whose modulation and coding are specified. In these systems, the mobile station communicates with a plurality of scattered base stations by transmitting and receiving bursts of digital information on the uplink and downlink RF channels.

Digital communication systems employ various techniques for processing erroneous received information. Generally speaking, these techniques may be applied to a technique that allows a receiver to correct for erroneous received information, such as foward error correction (FEC) techniques and techniques that cause erroneous received information to be retransmitted to the receiver, (FEC) techniques include, for example, convolutional or block coding of data prior to modulation. FEC coding is a technique that uses a certain number or more of code bits to generate a specific number It is common to refer to the convolutional code by a code rate such as 1/2 and 1/3, where it is common to refer to a convolutional code, The lower the code rate, the better the error protection is, and the lower the user bit rate for a given channel bit rate.

The ARQ technique includes a technique for analyzing whether an error exists in a received data block and a technique for requesting retransmission of a block including an error. For example, consider a block mapping example shown in FIG. 1 for a wireless communication system operating in accordance with Generalized Packet Radio Service (GPRS) optimization proposed as a packet data service for GSM. Here, a logical link control (LLC) including a frame header (FH), a payload of information, and a frame check sequence (FCS) includes a block header (BH), an information field, and a block check sequence (Which may be used to check if the receiver has an error in the information field). ≪ / RTI > The RLC blocks are further mapped to physical layer bursts, e.g., GMSK modulated radio signals on a carrier for transmission. In this example, the information contained within each RLC block may be interleaved over four bursts (time slots) for transmission.

When processed by a receiver, e.g., a receiver in a mobile radiotelephone, each RLC block may check for errors using a block check sequence and a known periodic redundancy check technique after demodulation and FEC decoding. If there is an error after FEC decoding, it sends a request to the transmitting entity, e.g. the base station of the wireless communication system, which means that the block should be retransmitted.

GPRS optimization provides four coding schemes (three different rates of convolutional code and one uncoded mode). If one of the four coding schemes is selected for the current LLC frame, segmentation of this frame to the RLC block is performed. If the RLC block needs to be resent at the receiver and needs to be retransmitted, then the initially selected FEC coding scheme is used for retransmission, for example, this system employs fixed redundancy for retransmission purposes. The retransmitted block may be combined with a previously transmitted version in a process, usually referred to as soft combining, as an attempt to successfully decode the transmitted data.

Another proposed technique is commonly referred to as variable redundancy, in which, if the initially transmitted block can not be decoded, an additional redundancy bit is transmitted. This technique is schematically illustrated in Fig. Here, three decoding attempts are made by the receiver. Initially, the receiver attempts to decode the initially received data block (with or without redundancy). If unsuccessful, the receiver receives the additional redundancy bit R1 and attempts to decode it with the originally transmitted data block. As a third step, the receiver acquires another redundancy information block R2 and attempts a third decoding using the initially received data and a block of redundancy bits R1. This process is repeated until successful decoding is achieved.

One problem with the technique illustrated in FIG. 2 is that the data blocks (and additional redundancy bit blocks) may not be decoded until successfully decoded, since subsequently transmitted redundancy blocks (e.g., R1 and R2) It requires a large amount of memory to store. This storage requirement is augmented by the fact that the receiver typically stores a multi-bit soft value associated with each received bit (such soft value represents the confidence level associated with decoding of the received bit). Such a problem is described in IEEE Transactions on Communications, Vol. 43, No. 6, pp. Can be partially solved by adopting the techniques described in Samir Kallel's "Complementary Punctured Convolutional (CPC) Codes and Their Applications," published in 2005-2009. Here, the authors disclose an error correction technique that allows previously transmitted blocks to be discarded when the memory space is not available, so that each retransmitted block can be decoded independently.

If soft combining or variable redundancy is adopted, explicit numbering of the transmitted blocks is required to distinguish between different information blocks and / or redundancy bits, so that the receiver can perform the proper block processing. This process is generally accomplished by assigning a sequence number to a block to be transmitted, and the receiver uses this to match previously received other blocks associated with the same data as the received block for combining / decoding.

It is also problematic to transmit the data indicated by the sequence number and the sequence number for the block. For example, if a sequence number is received incorrectly, the receiver may not be able to determine how to use the received information for decoding or soft combining. Several solutions have been proposed to solve the problem of protecting the sequence number. For example, it has been proposed that the sequence number be more thoroughly protected using a lower code rate than the payload data to which the sequence number is assigned. In this way, the receiver is more likely to receive the decodable sequence number, and is more likely to grasp, for example, how to properly match the previously received other block with the received block.

However, transmitting the sequence number with the payload data causes other inefficiencies in a wireless environment not resolved by known design schemes. When the sequence number and the payload data are transmitted at the same time and at the same frequency, there is a high probability that both of them are transmitted correctly or all are transmitted incorrectly. In a variable redundancy scheme, it is desirable to correctly decode the sequence number, block identifier, associated with incorrectly decoded payload data, in order to properly decode it by associating incorrectly decoded payload data with other sub-blocks.

Accordingly, it is desirable to provide a new technique for improving ARQ techniques, which reduces overhead signaling, improves the efficiency of memory utilization, and identifies sub-blocks in a manner that allows for more efficient variable redundancy processing.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to error handling in the field of communication systems, and more particularly to error handling using variable redundancy and automatic retransmission requests (ARQ) in a digital communication system.

1 is a diagram showing an information mapping in a conventional system operating by GSM.

2 is a diagram illustrating a conventional variable redundancy technique.

3A is a block diagram of a preferred GSM communication system of the present invention.

3B is a block diagram used to describe a preferred GPRS optimization for the GSM system of FIG. 3A.

4 is a diagram illustrating a receiver control ARQ according to a preferred embodiment of the present invention.

5 is a diagram illustrating a conventional GPRS format for a downlink data block.

6 is a diagram illustrating a format for a downlink data block according to a preferred embodiment of the present invention.

7A is a diagram illustrating a coding relationship between subblocks by one preferred FEC / ARQ scheme.

FIG. 7B shows the location of the stilling bits and is a diagram showing the mapping from the radio block to the TDMA frame in the preferred GPRS system.

8 is a diagram illustrating an uplink and downlink transmission sequence according to a preferred embodiment of the present invention.

9 is a diagram illustrating another format for a downlink data block according to another preferred embodiment of the present invention.

10 is a diagram illustrating signaling according to a preferred network control ARQ embodiment of the present invention.

The drawbacks and other drawbacks of the prior art methods and systems for communication information are overcome by the present invention in that the receiver controls the block order that is transmitted by the transmitter such that the transmitter need not include a sequence number for each transport block. In this way, the receiver can indirectly know which stored blocks or blocks, if any, should be processed in relation to recently received blocks, regardless of whether the latest received block was received with more than one error.

According to a preferred embodiment of the present invention, the receiver can send a transport block order message to the sender indicating a sequence order of the transmission. If the receiver incorrectly receives an information block and retransmission is required, the message indicates which block should be retransmitted and the location of the retransmission block within the next set of blocks to be transmitted. In this way, the receiver can know exactly which block is received without including the sequence sequence number in each transmitted data block.

According to another preferred embodiment of the present invention, the receiver can notify the transmitter of the block sequence per block. For example, the receiver itself may send blocks of data containing a transmission control field to the transmitter. The transmission control field specifies the block number of the next block that the transmitter should deliver to the receiver. If the block is to be retransmitted (or if additional redundancy bits associated with previously transmitted blocks should be provided), the value in the transmission control field reflects the sequence number of the previously transmitted block.

In a packet data system, channels may be shared among a plurality of mobile stations. For example, if one mobile station only receives data on the downlink portion of the channel pair and the other mobile station only transmits data on the uplink portion of the channel pair, the former mobile station transmits the transmission control field Lt; / RTI > However, the latter mobile station is identified in the downlink transmission by the uplink state flag so that the former mobile station ignores the system's indication of which block is to be transmitted next.

According to another preferred embodiment of the present invention, the transmitter may forward a message to the receiver informing the receiver of the sequence of the subsequent block transmission. The transmitter can then transmit the data blocks in the predetermined order without attaching a sequence number.

By separating the transmission of payload data from the block and sub-block identifiers, a robust bond redundancy technique is created. For example, a group of block sequence numbers may be transmitted together as a bitmap, whereby the individual sequence number need not be fully specified. Instead, the starting sequence number can be fully specified, and the additional sequence number is indicated by the increment from the subsequent offset or start sequence number.

Hereinafter, a preferred embodiment of a TDMA wireless communication system will be described. However, those skilled in the art will appreciate that the present connection method is used for illustrative purposes only and that the present invention can be readily applied to all kinds of connection methods including frequency division multiple access, TDMA, code division multiple access, and a combination thereof Will recognize.

In addition, the operation by the GSM communication system described in ETS 300 573, ETS 300 574, and ETS 300 578 of the European Telecommunications Standards Institute (ETSI), which is hereby incorporated by reference, is also described. Therefore, we describe herein only the operation of the GSM system in conjunction with the proposed GPRS optimization scheme (hereinafter referred to as GPRS) for packet data only to the extent of understanding the present invention. Although the present invention is described as a preferred embodiment in a GPRS system, those skilled in the art will recognize that the invention may be used in a wide variety of digital communication systems, such as digital communication systems based on wideband CDMA or wireless ATM.

A communication system 10 according to a preferred GSM embodiment of the present invention is shown in Figure 3 (a). System 10 is designed as a hierarchical network with multiple levels to handle calls. Mobile stations 12 operating within the system 10 using a set of uplink and downlink frequencies are involved in the call using the time slots assigned to them on these frequencies. At the higher layer level, a group of mobile switching centers (MSCs) 14 is responsible for establishing a call path from the caller to the target point. In particular, the above entities are responsible for setting up, controlling and terminating calls. One of the MSCs 14, known as the gateway mobile switching center, handles communications with the Public Switched Telephone Network (PSTN) 18, or other public or private networks.

At the lower layer level, each mobile switching center 14 is connected to a group of base station controllers (BSC) 16. Under the GSM standard, the BSC 16 communicates with the MSC 14 via a standard interface known as the A-interface, which is the CCITT signal system No. 1. 7. Based on the moving application part.

At a lower hierarchical level, each of the BSCs 16 controls a group of base transceiver stations (BTS) 20. Each BTS 20 includes a number of TRXs (not shown) that utilize the uplink and downlink RF channels to service a particular common geographic area, such as one or more communication cells 21. The BTSs provide essentially RF links for the transmission and reception of data bursts to / from the mobile station 12 in the assigned cell. When used to transmit packet data, the channels are often referred to as packet data channels (PDCHs). In a preferred embodiment, a plurality of BTSs 20 are included in a radio base station (RBS) 22. For example, the RBS 22 may be configured according to the RBS-2000 family of products, a product of Telefonaktiebolaget L M Ericsson, the assignee of the present invention. Further details regarding the implementation of the preferred mobile station 12 and RBS 22 are found in US patent application Ser. No. 08 / 921,319 entitled " A Link Adaptation Method For Links Using Modulation Schemes That Have Different Symbol Rate " issued to Magnus Frodigh et al. And inserts the disclosures into the present application by reference.

The advantage of introducing a packet data protocol in a cellular system is that it allows the transmission of high data rates and at the same time the bandwidth of the radio frequency on the air interface is flexible and efficient to use. The above GPRS concept is designed for so-called " multi-slot operation " in which one user is allowed to occupy one or more transmission resources at the same time.

3B shows an overview of the GPRS network described above. Since GPRS is one of the optimizations of GSM, many nodes and entities in the network are similar to those described for FIG. 3A. Information packets from the external network enter the GPRS network at the Gateway GPRS Service Node (GGSN) 100. Next, the packet is transmitted from the GGSN to the Serving GPRS Support Node (SGSN) 140 via the backbone network 120, which provides the service of the area where the designated GPRS mobile terminal is located. The packet is transmitted from the SGSN 140 to the correct base station system (BSS) 160 via dedicated GPRS transmission. The BBS has a plurality of base transceiver stations (BTS) 180 and a base station controller (BSC) 200, and only one BTS is shown in the figure. The connection between the BTSs and the BSCs is referred to as the A-bis interface. The BSC is a representation used exclusively by GSM, and in other typical systems the term Radio Communication Control (RNC) is used for nodes having similar functions to BSC. Next, the BTSs 180 transmit the packets on the wireless interface to the remote device 210 in accordance with the selected information rate.

The GPRS register holds the subscriber data of all GPRS. The GPRS register may or may not be integrated into the Home Location Register (HLR) 220 of the GSM system. The SGSN and the MSC / VLR 240 may exchange subscriber data to ensure services such as limited service switching. The connection network interface between the BSC 200 and the MSC / VLR 240 is a standard interface known as the A-interface. 7. Based on the moving application part. In addition, the MSC / VLR 240 provides connectivity to the terrestrial network system via the PSTN 260.

As described above, the system 10 may support retransmission techniques such that the receiving entity (MS 210 or RBS 180) may retransmit the RLC block (or the redundancy bit associated with the RCL block) ) Or RBS 180). According to a preferred embodiment of the present invention, since the block sequence number is separated from the transmission of the data block itself, the receiver can know the sequence number of the receiving block substantially without being transmitted with the payload data.

In the above example, a transmitter (e.g., a mobile terminal) sends a channel request message to a receiver (e.g., a base station) to forward seven information blocks To be done. In response to the request, the receiver sends a message to the transmitter informing it to receive the blocks in a specified order. The message may be a fraction of the total blocks to be transmitted (four in this example). For example, the message may be in the form of a bitmap with the start sequence number fully specified as 6 or 7 bits, and subsequent sequence numbers in the same order are specified in increments from the start sequence number. Next, the transmitter transmits the blocks according to the indicated order without adding the sequence numbers. The receiver processes each block received according to the above technique (e.g., a variable redundancy technique) using knowledge of the sequence order defined in the RX_BLOCK_ORDER message. As part of the process, the receiver determines whether any received blocks need to be retransmitted with additional redundancy bits to decode the block again, including uncorrectable errors.

After the first four blocks have been transmitted and received, the receiver sends a second RX_BLOCK_ORDER message specifying the desired order for the remaining blocks to be transmitted in the future. As shown in FIG. 4, the receiver requests, through a second message, to transmit a first set of redundancy bits for one of the first received blocks, i. E., Redundancy bit R1 for block 2. In the above example, the receiver first specifies to transmit R1 for block 2 and then to transmit blocks 5, 6 and 7. Receiving the redundancy bit R1 for block 2 allows the receiver to easily associate the redundancy information with previously received (and stored) block 2 because it recognizes the redundancy bit using the request message sent to the transmitter, A second decoding attempt may be performed, as shown. In this way, the receiver can correctly process the received blocks without correctly decoding the sequence number transmitted with each block. In order to more specifically describe a method of using the technique, a more detailed embodiment will be described below.

First, in a preferred embodiment, the base station is a packet data receiver and the mobile station is a packet data transmitter. Therefore, the base station informs the mobile station of the order of the packets to be transmitted through the uplink on the downlink. In the preferred GPRS embodiment, the notification may be performed by extending the GPRS MAC header, which includes the sequence number of the block to be transmitted by the mobile station in the next block period on the uplink, do. 5, the block format includes a MAC header including an uplink status flag USF, a secondary / polling bit S / P, a relative reserved block period RRBP, and a payload scheme PT, An RLC data block including an RLCH header and payload data, and a MAC header composed of a block acknowledgment sequence (BCS).

As in the current GPRS system, a sequence number may be appended to the blocks to be transmitted. However, according to a preferred embodiment of the present invention, the network, along with each downlink block transmitted to one mobile station or mobile stations sharing the same packet data channel (PDCH), updates the sequence number of the block to be transmitted by the mobile station Can be included in the link. Only one mobile station having a USF reservation in the MAC header for a specified block (i. E., Having an identifier in the USF field), despite the fact that multiple mobile stations can use the same PDCH, To determine the transmission of the next block (e.g., the next new block) or the transmission of the retransmission / redundancy bits associated with the previous block. The sequence number can be transmitted, for example, via a newly defined field of the MAC header, namely a field called a transmission control flag (TCF), which is illustrated in FIG. Moreover, until the decoding is successful, the same sequence number can be repeatedly transmitted on the downlink several times in order to retransmit (soft combine) or transmit another redundancy unit (variable redundancy) associated with a particular block.

According to a preferred embodiment of the present invention, the TCF field of the downlink block may be used to request retransmission / transmission of a redundancy unit for a block that was erroneously received during the next block period following the erroneous reception. This will significantly reduce the need for receiver memory because only a minimum number of blocks at a given time point are outstanding (i.e., waiting for successful decoding). Similarly, this scheme helps to transmit within a relatively small transmission window size than conventional retransmission schemes, which means that a smaller sequence number, for example, less than 7 bits, can be used. By reducing the sequence number, it reduces the band associated with the useless signal for the downlink TCF field and the block being transmitted on the uplink (when transmitting the sequence number on the uplink).

Under certain circumstances, such as an error correction technique involving retransmission using a lot of coding and soft combining, it is useful to identify which version of a particular block (called a " sub-block number ") is being processed. This concept is illustrated in Fig. 7 (a), in which four sub-blocks associated with the same radio block are shown. Here, sub-block 1 represents the original uncoded data. Sub-block 2 indicates that one redundancy bit block has been added to the data, which is equivalent to a half coding rate. Similarly, sub-block 3 and sub-block 4 add two and three redundancy bit blocks to the data, respectively, corresponding to 1/3 and 1/4 coding rates, respectively. By allowing the receiver to request the transmission of a particular sub-block, the network can request retransmission of the received sub-block with, for example, the lowest carrier-to-interference ratio (C / I).

To designate a sub-block number according to the present invention, a so-called stealing bit is used in the preferred embodiment of the present invention. Originally, the term "stealing bit" came from the fact that voice and line services are exchanged in GSM. Thus, when an emergency signal is to be transmitted to the receiver, the transmitter, for example, replaces the complete voice frame with a signaling message. Thus, the signaling message is referred to as " stolen " a voice frame and is indicated by a stealing flag or a stealing bit.

The location of the stilling bits in the physical layer is shown in Figure 7 (b). These stilling bits are still mentioned using this name, but they are used for various purposes in GPRS systems. As shown, in the GPRS system, a radio block including 456 bits is transmitted in four TDMA frame periods, where there is one burst in each frame. One burst occupies one slot in a TDMA frame. Different puncturing schemes can be used to obtain different FEC coding rates. For example, four coding rates are specified in GPRS (e.g., 1/2, 2/3, 3/4, 1). The coding rate used for a particular radio block is specified using a stilling bit. Since the radio block includes two stealing bits per burst and is transmitted on four bursts, eight bits can be used to indicate the coding rate.

The preferred embodiment according to the present invention uses stilling bits for other purposes. In the case of using hybrid ARQ or soft combining, such a coding technique is not required, and according to the present invention, such a stilling bit can be used to specify a sub-block number associated with a specific transmission / reception. In particular, a code word which is an 8-bit code of Hamming distance 5, which is also compatible with the reverse direction shown in Table 1 below, can be arbitrarily assigned to a unique sub-block number.

Sub-block number Codeword One 1111 1111 2 1100 1000 3 0010 0001 4 0001 0110

Alternatively, it may be necessary to explicitly specify the sub-block number, in which case the TCF field may be extended (e.g., by 2 bits) to specify the block and sub-block number.

8 shows an example of a receiver control ARQ according to a preferred embodiment. Here, the upper level of the rectangle indicates an uplink packet transmitted by the mobile station to the network having the sequence number SN = k, 1, k is the block number and 1 is the sub-block number. These numbers are not explicitly transmitted by the mobile station, as described above. The lower level of the rectangle represents the downlink packet that the network sends to the mobile station (a group of mobile stations sharing the channel), which specifies the sequence number of the next packet to be transmitted in addition to the specific USF value. In this example, both users i and j share the same PDCH for transmission to the network. In this example, it can be seen that when the network requests a new block, that is, a block that has not been transmitted before, any unspecified default value D can be transmitted as the TCF value. Of course, those skilled in the art will appreciate that the network need only transmit the actual sequence number in all cases without having to use a default. If the CRC fails for a particular block received by the network, the network will specify that the block should be retransmitted / retransmitted and / or transmitted a redundancy bit for this purpose. This is illustrated in FIG. 8 by a second uplink block (SN = 8, 1) designated as having a failed CRC. The next downlink block contains the TCF value associated with the erroneously received block # 8, thereby indicating that the mobile station transmits block # 8 and sub-block # 2 in the next time slot.

If a USF assignment is requested, the network may need to provide continuous downlink transmission. Otherwise, for example, if only one user is assigned to a particular PDCH, then the network may not be able to transmit downlink packets to each available time slot. In this case, the mobile station may equate the transmission fault with the request for the next packet on the sequence, as if the default TCF value was transmitted.

In the preferred embodiment, a focus is placed on a base station operating as a receiver and a mobile station operating as a transmitter, in which case the receiver controls the order of blocks to be transmitted. The present invention is also applicable to the opposite situation, and a preferred embodiment thereof will be described below. As on the uplink, multiple temporary block flows (TBFs) can be multiplexed on a single downlink PDCH. However, this approach becomes more complicated to support variable redundancy since the intended mobile receiver must also be explicitly identified on the downlink.

As mentioned above, different mobile stations transmitting on a single PDCH are distinguished using the USF field. Specifically, the network indicates which mobile station the block requesting the network to transmit on the uplink is from. According to the present invention, this same technique may be used by the downlink to specify to which mobile station a particular downlink data block is directed. Thus, as shown in FIG. 9, the downlink status field (DSF) is appended to the MAC header identifying the mobile station in the same manner as the USF, i.e., using the same identification numbering scheme, the same coding. As described above, USF and DSF can be transmitted on the downlink. The USF refers to the mobile station transmitting on the uplink in the next block period, and the DSF specifies the mobile station in the group sharing the same downlink PDCH. If the payload data transmitted on the downlink is for another mobile station, the USF and DSF may have different values from the transmission request specified by the USF.

In a manner similar to that described for the preferred embodiment of FIG. 4, the order of blocks transmitted from the network may be relayed to the mobile station by the network using a TX BLOCK ORDER message. This message may be sent to the mobile station as part of the packet downlink assignment message or may be sent in response to an acknowledgment / disapproval (ACK / NACK) message from the mobile station. Fig. 10 shows an example of this signal. Here, the network assigns the downlink PDCH to the mobile station and designates to transmit the block # 1-4 first. After transmitting these four blocks, the mobile station acknowledges reception of blocks # 1, 3 and 4 but does not approve of block # 2. The network then informs the mobile station that it will resend block # 2 (with / with an additional redundancy bit) and that block # 5 will follow. The network sends a message indicating that Blocks # 6 and 7 are to be sent following this signal and sends this block.

In addition to being part of the assignment message or accompanied by an ACK / NACK message from the mobile station, the TX BLOCK ORDER message may be delivered whenever it is deemed necessary in the network. Thus, the mobile station carries the sequence numbers specified in accordance with the most recently received TX BLOCK ORDER message from the network.

The format of the TX BLOCK ORDER message depends on design considerations, as will be appreciated by those skilled in the art. However, a format similar to the format conventionally used for the ACK / NACK message may be used, in which a bitmap representing sequence sequences of blocks is transmitted. For example, if the stilling bits are used to represent sub-block numbers, the bitmap takes the form shown in Table 2 below, where the starting sequence number is 1 and each bit indicates whether a particular block should be sent . Thus, Table 2 describes a TX BLOCK ORDER message, where blocks # 1-4 are to be transmitted. That is, the first 4 bits of the bitmap are 1, and the subsequent bits are 0.

S S N = One One One One One 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Other forms for TX BLOCK ORDER messages can be used if sub-block numbers need to be explicitly defined in a TX BLOCK ORDER message, i.e., because the stilling bits can not be used to represent sub-block numbers. For example, Table 3 shows a bitmap format indicating to the mobile station that the network is to transmit to the mobile station block # 2b and subsequently block # 5a, i.e., the first transmission associated with the second transmission and block # 5 associated with block # 2 do.

S S N = 2 One O O O O O O One 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

In this example, the starting sequence number is 2, and each two consecutive bits of the bitmap means a block and sub-block number combination, as further described in Table 4. [

00 No transmission 01 Sub-block a 10 Sub-block b 11 Sub-block c

Thus, in the example of Table 3, the first two bits, '10', means that block # 2 is transmitted to version 2b, and the next two bits '00' fields indicate that blocks # 3 and # 4 are not transmitted , And a subsequent '01' field means that block # 5 is transmitted to version 5a, i.e., its first transmission.

In summary, embodiments of the present invention provide an alternative mechanism for block addressing that may be applied, for example, to packet data transmission in a wireless communication system. The present invention provides, among other things, separation of the transmission of payload data and its associated sequence number. For example, before a transmitter transmits a block of data on the uplink, the receiver may request to transmit a particular block to the transmitter on the downlink. As such, the transmitter need not transmit the sequence number with the data block to be transmitted. For example, if the downlink and uplink channels are at different times during operation in FDD (frequency division duplex) mode and at different times during operation in TDD (time division duplex) mode, Number and associated data blocks at different times and / or different frequencies. By separating the transmission of payload data from the block and sub-block identifiers, a more robust variable redundancy technique becomes possible. For example, the block sequence numbers may be transmitted together as bitmaps, thereby eliminating the need for the individual sequence numbers to be fully specified. Instead, the starting sequence number can be perfectly specified, and the other sequence numbers are indicated by a subsequent offset or increment from the starting sequence number.

Further, since the TCF for uplink data transmission also serves as an ACK / NACK message, the present invention reduces the memory requirement. Therefore, when a block miss occurs, the sequence number is transmitted immediately through the TCF, and the redundancy / retransmission is performed within the next block period. Additionally, efficiency is increased because less ACK / NACK messages are used.

While the invention has been described in some detail by way of a few preferred embodiments, those skilled in the art will appreciate that various modifications are possible without departing from the invention. The block sequence message or transmission control field may contain more information than the sequence number. For example, if two or more blocks / sub-blocks are transmitted together within one block period by interleaving blocks / sub-blocks within one block period (e.g., a 4TDMA burst as shown in FIG. 7B) The message or transmission control field may contain information associated with the method of performing the extraction of the blocks / sub-blocks concerned as well as the identification numbers of the various blocks / sub-blocks. Accordingly, the invention can be limited only by the following claims, which include all equivalents

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Claims (21)

In a wireless communication system, A mobile station that transmits a plurality of data blocks on an uplink channel and includes a first processor; And Receiving the plurality of data blocks on the uplink channel, ≪ / RTI > The base station determining a desired sequence order in which the plurality of blocks are to be transmitted by the mobile station; The base station transmits to the mobile station information specifying a sequence order in which the mobile station should transmit the plurality of data blocks; The first processor processes the information and controls transmission of the plurality of blocks accordingly; The second processor receives the plurality of blocks in the desired order and processes each block based on the sequence number And the wireless communication system. The wireless communication system according to claim 1, wherein the base station transmits, as the information, a block sequence message specifying a transmission order of a plurality of data blocks. 2. The method of claim 1, wherein the base station further comprises: as the information, a transmission control field in a downlink block on a downlink channel, the transmission control field designating a sequence number of a next block to be transmitted by the mobile station And transmits the message to the mobile station. 4. The wireless communication system according to claim 3, wherein the transmission control field includes a default value when the base station does not request retransmission. 4. The system of claim 3, wherein the uplink channel and the downlink channel are transmitted using different transmission parameters including at least one of different frequencies, different time slots, and different spreading codes. The wireless communication system according to claim 1, wherein the mobile station transmits the plurality of blocks in the sequence order without attaching the sequence numbers. 2. The system of claim 1, wherein the sub-block number is specified by mapping a stealing bit. 4. The system of claim 3, wherein the transmission control field also specifies a sub-block identifier. 3. The wireless communication system of claim 2, wherein the block order message is a bitmap comprising an initiation sequence number followed by one or more increments of the initiation sequence number. A method for transmitting a plurality of blocks of information from a transmitter to a receiver in a wireless communication system, The receiver requesting a specific sequence to which the plurality of blocks should be transmitted by sending a message to the transmitter specifying the sequence; And Transmitting the plurality of blocks to the receiver to the transmitter in the sequence ≪ / RTI > 11. The method of claim 10, Further comprising the step of transmitting the plurality of blocks without attaching a sequence number thereto. 11. The method of claim 10, wherein the receiver is a base station in the wireless communication network and the transmitter is a mobile station. 11. The method of claim 10, wherein the plurality of blocks comprises a retransmission / redundancy information block associated with another information block previously transmitted to the receiver. A method for communicating a plurality of information blocks from a transmitter to a receiver in a wireless communication system, Transmitting, by the transmitter, a message specifying a sequence order in which the plurality of blocks are to be transmitted; The transmitter transmitting the plurality of blocks to the receiver in the sequence; And The receiver processing each of the plurality of blocks using a sequence number obtained from the message specifying the sequence order ≪ / RTI > 15. The method of claim 14, Recognizing from the message that the received block contains information relating to a block previously received; Calling the previously received block from memory; And Attempting to decode the received block and the previously received block together ≪ / RTI > 15. The method of claim 14, wherein the second step of the transmission comprises: And transmitting the plurality of blocks without attaching a sequence number thereto ≪ / RTI > 15. The method of claim 14, wherein the receiver is a mobile station in the wireless communication network, and wherein the transmitter is a base station. 15. The method of claim 14, wherein the plurality of blocks comprises a retransmission / redundancy information block associated with another information block previously transmitted to the receiver. 11. The method of claim 10, wherein the request is comprised of a bitmap comprising one or more increments of an initiation sequence number followed by the initiation sequence number. 15. The method of claim 14, wherein the request is comprised of a bitmap comprising one or more increments of an initiation sequence number followed by the initiation sequence number. 4. The system of claim 3, wherein the transmission control field also provides information about interleaving the plurality of blocks.