KR101301368B1 - Method and arraratus of transmitting and receiving for forward shared control channel in mimo system - Google Patents

Abstract

The present invention provides an apparatus and method for transmitting and receiving a downlink common control channel in a mobile communication system.

The present invention is characterized in that a downlink control channel is configured using only transmission resources required according to an active transmission layer (rank) in a mobile communication system supporting a multi-antenna technology. Therefore, it provides an advantage of optimizing the amount of control information according to the downlink control channel configuration.

Precoding, codebook, single codeword (SCW), double codeword (DCW), transmission layer (rank)

Description

Device and method for transmitting / receiving downlink common control channel in mobile communication system {METHOD AND ARRARATUS OF TRANSMITTING AND RECEIVING FOR FORWARD SHARED CONTROL CHANNEL IN MIMO SYSTEM}

1 is a diagram illustrating a structure of a transmission / reception apparatus of an SCW MIMO to which the present invention is applied.

2 is a diagram showing the structure of a DCW MIMO transceiver apparatus to which the present invention is applied;

3 is a diagram illustrating a structure of a DL control channel in SCW MIMO to which the present invention is applied;

4 is a diagram illustrating the structure of a DL control channel in DCW MIMO to which the present invention is applied;

FIG. 5 is a diagram illustrating a structure of a DL control channel according to blind detection proposed in the first embodiment of the present invention. FIG.

6 is a signal flow diagram for receiving a DL control channel according to a first embodiment of the present invention.

7 is a diagram illustrating a structure of a DL control channel according to separate encoding proposed in the second embodiment of the present invention.

8 is a signal flow diagram for receiving a DL control channel according to a second embodiment of the present invention.

9 is a diagram showing the structure of a transmitting device according to the present invention;

10 is a diagram showing the structure of a receiving device according to the present invention;

The present invention relates to a mobile communication system, and more particularly, to a method and apparatus for transmitting and receiving a downlink shared shared control channel (F-SCCH) in a mobile communication system supporting multiple antenna technology.

The mobile communication system has evolved into a high-speed, high-quality wireless packet data communication system for providing data service and multimedia service, instead of providing an initial voice-oriented service.

Recent 3GPP High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), 3GPP2 High Rate Packet Data (HRPD) Various mobile communication standards such as IEEE 802.16 are being developed to support high speed and high quality wireless packet data transmission service.

Third generation wireless packet data communication systems such as HSDPA, HSUPA, and HRPD mentioned above use techniques such as adaptive modulation and coding (AMC) and channel sensitive scheduling to improve transmission efficiency.

By using the AMC method, the transmitting device may adjust the amount of data to be transmitted according to the channel state. In other words, if the channel condition is bad, the amount of data to be transmitted can be reduced to reduce the reception error probability to the desired level, and if the channel condition is good, the reception error probability can be increased to the desired level and a lot of information can be effectively transmitted. .

In addition, when the channel sensitive scheduling resource management method is used, the transmitting apparatus selectively services a user having a good channel state among several users, thereby increasing system capacity compared to allocating and serving a channel to one user. This increase in system capacity is called the multi-user diversity gain.

In short, the ACM method and the channel sensitive scheduling method are methods of receiving feedback of partial channel state information from a receiving apparatus and applying an appropriate modulation and coding technique at a time point determined to be the most efficient.

In order to realize the ACM method and the channel sensitive scheduling method, the receiving apparatus needs to feed back channel state information to the transmitter. The channel state information fed back by the receiver is referred to as a channel quality indicator (CQI).

On the other hand, Orthogonal Frequency Division Multiple Access (OFDMA), which is a code division multiple access (CDMA), which is a multiple access scheme recently used in second and third generation mobile communication systems, in a next generation system. Research is actively underway to change this.

In this regard, 3GPP and 3GPP2 are proceeding standardization of the evolution system using OFDMA. Evolution systems employing the OFDMA scheme as compared to the CDMA scheme are expected to increase system capacity.

One of various causes of capacity increase in the OFDMA scheme is that frequency domain scheduling (Frequency Domain Scheduling) may be performed. That is, as the channel gains the capacity gain through the channel sensitive scheduling method according to the characteristic that the channel changes over time, more capacity gain can be obtained when the channel utilizes different characteristics according to the frequency.

However, in order to support frequency domain scheduling, a transmitting apparatus must grasp channel state information for each frequency. In this case, since CQI feedback is required for each frequency, there is a disadvantage in that the signaling burden due to the CQI feedback transmission and reception is increased from the viewpoint of the receiving apparatus and the transmitting apparatus.

Meanwhile, in the next generation system, the introduction of a multiple input multiple output (MIMO) technology using multiple transmit / receive antennas has been actively studied. MIMO technology is a technology for transmitting a plurality of data streams using the same resources at the same time using multiple transmit and receive antennas. The MIMO technique is known to transmit a plurality of low modulation order data streams to increase the amount of transmission at the same error probability, rather than increasing the modulation order when the channel condition is good. In the MIMO scheme, a dimension in which individual data streams are transmitted is called a layer, and applying the AMC according to the channel state of each layer is effective to increase the overall system capacity.

For example, Per Antenna Rate Control (PARC) is a technology for transmitting different data streams for each transmit antenna, where the layer becomes each transmit antenna. In this case, each of the plurality of transmit antennas experiences a different channel. In the PARC scheme, the AMC is applied so that more data can be transmitted to a transmit antenna having a good channel state, and the amount of data transmitted is reduced to a transmit antenna having a poor channel state. .

Another example is Per Common Basis Rate Control (PCBRC), which is a layer-fixed transmit beam. Therefore, in the PCBRC technique, more data is transmitted through a transmission beam having a good channel condition, and the amount of data transmitted is reduced with a transmission beam having a poor channel condition. In addition, when implementing MIMO using multiple antennas, a precoding method is used to adaptively form a transmission beam according to channel conditions. Here, precoding (hereinafter referred to as "precoding") means pre-distorting a transmission signal in a step before transmitting a signal from a transmission apparatus to a transmission antenna. If precoding is implemented as a linear combination, the precoding process can be written as in Equation 1.

x = Es

1 크기의 벡터로 전송하고자 하는 신호를 나타내고, x는 M

1 크기의 벡터로 실제 전송하는 신호를 나타낸다. 단 K는 MIMO를 통해 동시에 동일 자원으로 전송되는 심볼의 수이며 M은 송신 안테나의 수이다. E는 N

K 크기의 행렬로 precoding을 나타낸다. 즉, <수학식 1>은 M개의 송신 안테나를 갖춘 MIMO 송신 장치에서 K개의 신호열을 동시에 전송할 때, E라는 사전부호화 방식을 적용하는 것을 표현한 것이다. Where s is K

Represents a signal to be transmitted as a vector of one magnitude, and x is M

Represents a signal that is actually transmitted as a vector of size 1. Where K is the number of symbols transmitted simultaneously on the same resource through MIMO and M is the number of transmit antennas. E is N

A matrix of size K indicates precoding. That is, Equation 1 expresses the application of a precoding scheme of E when simultaneously transmitting K signal strings in a MIMO transmitting apparatus having M transmit antennas.

The pre-coding matrix E is adaptively determined according to the transmission MIMO channel. However, when the transmitting apparatus cannot know the information about the transmitting MIMO channel, the transmission encoding is performed according to the feedback information reported by the receiving apparatus. To this end, a precoding codebook including a finite number of precoding matrices E is set in advance between the transceivers. The receiving device selects the most preferred precoding matrix E from the precoding codebook in the current channel state, feeds it back to the transmitter, and the transmitting device applies the precoding to perform MIMO transmission.

In addition, a signal in which the transmission signal of Equation 1 is received through the MIMO channel H is represented by Equation 2 below.

y = Hx + z = HEs + z

1 크기의 벡터로 각각 N개의 수신 안테나에 수신된 신호와 잡음 신호를 나타내고 H는 N

M 크기의 행렬로 MIMO 채널을 나타낸다. 수신 신호는 수신 결합 과정을 거쳐 각 계층의 송신 신호열의 SINR(Signal to Interference and Noise Ratio)이 개선되도록 한다. 수신 결합 과정을 거친 신호 r은 <수학식 3>과 같다.Where y and z are N

A vector of one magnitude represents a signal and a noise signal received at N receive antennas, respectively, where H is N

A matrix of size M represents a MIMO channel. The received signal is subjected to a receive combining process to improve the signal to interference and noise ratio (SINR) of the transmission signal sequence of each layer. The signal r which has undergone the reception combining process is shown in Equation 3.

r = Wy = WHx + Wz = WHEs + Wz

N 행렬로 수신 결합 과정을 나타내고 r은 N

1 신호 벡터이다. 각 계층의 송신 신호열을 보다 잘 수신하기 위해 추가적으로 간섭제거나 ML(Maximum Likelihood, 이하 ML) 수신 등의 수신 기법을 사용할 수 있다. Where W is N

Represent the receive combining process with an N matrix, where r is N

1 signal vector. In order to better receive the transmission signal sequence of each layer, a reception technique such as interference interference or ML (Maximum Likelihood (ML) reception) may be used.

There are a single codeword (SCW) scheme and a multi-codeword scheme, depending on how many encoded packets are generated from the multiple signal sequences transmitted by the MIMO scheme.

In the single codeword (SCW) scheme, one codeword is transmitted through a plurality of layers created by the MIMO scheme, regardless of the number of layers, and the multiple codeword scheme is one in each of the plurality of layers created by the MIMO scheme. Is to transmit a codeword.

An advantage of the multiple codeword scheme is that the receiving side can take an additional gain through a receiving process such as an interference canceller. This is because the receiving device can determine whether the decoding of each codeword succeeds through a cyclic redundancy check (CRC) applied to each codeword. However, as the number of transmission codewords increases, there are disadvantages such as the consumption of additional resources that increase linearly to apply the CRC, and the complexity of the receiving device.

Complementing the above disadvantages, there is a dual codeword (DWW) method as a compromise for obtaining a transmission rate improvement effect of the multiple codeword method. In the DCW scheme, up to two codewords are transmitted through a plurality of layers created by the MIMO scheme regardless of the number of layers.

1 illustrates an example of a structure of a transceiver for SCW MIMO to which the present invention is applied.

Referring to FIG. 1, a data string to be transmitted is converted into one encoded packet signal string through channel encoding and modulation process 101. This signal sequence is demultiplexed 103 into K signal sequences for MIMO transmission. The K multiplexed signal sequences are linearly converted into M signal sequences to be transmitted to each transmission antenna via the pre-encoder 105. This process may be regarded as processing the K signal sequences to be transmitted to different transmission beams.

The M pre-coded signal strings are transmitted to the transmission antennas 109a and 109m through the transmission processors 107a and 107m, respectively. The transmission processors 107a and 107m include not only a process of generating a CDMA or OFDMA signal, but also a filtering or radio frequency (RF) process performed at each antenna.

The transmitted signals are received by the N multiple receive antennas 111a and 111n, and each of the signals received through the receive antennas is restored to the baseband signal via the receive processors 113a and 113n. The received processed signal is passed through the receive combiner 115 and then multiplexed 117 is restored to the signal sequence originally intended to be transmitted. Finally, the demodulation and channel demodulation 119 restores the data sequence originally intended to be transmitted.

As described above, the SCW MIMO is characterized in that only one CQI needs to be fed back because a plurality of transmission signal sequences are generated by applying one channel encoding and modulation 101. However, the number of MIMO transmitted signal strings, that is, the number K of transmitted MIMO layers should be adjusted according to the channel state. Hereinafter, in the present invention, the number K of transport layers of a transmitted MIMO system is referred to as rank. Accordingly, the feedback of the SCW MIMO is composed of one CQI representing the channel state of the transmitting MIMO layer and rank, which is the number of transport layers.

2 illustrates an example of a structure of a DCW MIMO transceiver apparatus to which the present invention is applied.

Referring to FIG. 2, unlike SCW MIMO, two different encoded packet signal sequences are transmitted through the MIMO layer.

The data stream to be transmitted is demultiplexed into two data streams 201, and the demultiplexed data streams become modulated signal streams through different channel encoding and modulations 201-1 and 201-2, respectively. The following transmission process is the same as that of SCW MIMO. A signal to be transmitted to M transmit antennas 209a and 209m is generated through a precoding process 205 and transmission processes 207a and 207m for each transmit antenna.

The receiving process of DCW MIMO is also the same as the receiving process of SCW MIMO. In particular, although FIG. 2 illustrates a structure of a receiving apparatus utilizing the interference canceller 205, other types of receiving methods may be used.

The signals received by the N reception antennas 211a and 211n are sequentially passed through the reception processors 213a and 213n and the reception combiner 215, and then restored to the transmission signal for each layer. These recovered signals contain mutual interference. Since DCW MIMO performs different encoding and modulation for each layer, the receiver may first remove a signal of a specific layer to be restored so that the signal does not interfere with another layer.

By utilizing the interference canceller 219, the channel capacity of the MIMO layer can be improved, and thus more data can be transmitted through DCW MIMO transmission. The reception process through interference cancellation will be described as follows. If a modulation signal sequence is successfully recovered through demodulation and channel decoding 217, the recovered signal is used to remove interference (219). The signal sequence 223 from which the interference is removed is transferred to the demodulation and channel decoding process 217 to restore the second modulated signal sequence. Finally, the two restored data strings are restored to one data string to be transmitted through multiplexing 221.

On the other hand, the transceiver structure of the MCW MIMO is not significantly different from the transceiver structure of the DCW MIMO. A transmitter supporting MCW MIMO transmits different codewords for each MIMO layer created through precoding, while a receiver supporting MCW MIMO performs demodulation and channel decoding for each layer, and the signal sequence is first restored. Interference cancellation, demodulation, and channel decoding are repeated until all interferences are removed while eliminating contributing interference. In the following description of the present invention, since the operation of the DCW MIMO can be easily inferred, a detailed description of the operation of the MCW MIMO is omitted.

Hereinafter, a downlink control channel will be described. The downlink (DL) control channel is a channel including control information necessary for a terminal to recover a signal transmitted from a base station. In general, the information included in the downlink control channel is as follows.

1. UE ID (UE Equipment ID): UE ID is information for identifying whether there is a signal transmitted to the terminal.

In general, since the CRC according to a specific UE ID is inserted into the DL control information, if the terminal successfully restores the DL control information, the control information is recognized as information for the corresponding terminal.

2. Downlink resource block (DL RB) allocation information: If the terminal successfully restores DL control information, it is recognized through which DL RB information its actual data is transmitted.

3. Transport Format (TF): TF represents a modulation and coding scheme of a transmitted signal. If AMC is applied, the terminal must know the TF to perform the demodulation and decoding process.

4, Hybrid Automatic Repeat request (HARQ) Related information: HARQ sends a transmitter to the transmitter whether the receiver has successfully received the transmission packet, if the receiver successfully receives another transmitter and fails to receive If so, the transmitter retransmits the previous packet. The HARQ-related information refers to information related to HARQ such as initial transmission or retransmission. Based on this, the terminal determines whether to decode or perform a new decoding operation by combining with a previous received packet.

In the case of MIMO transmission, additional information must be transmitted to the DL control channel in addition to the above four information. In this case, if precoding is applied, the precoding information should be added to the DL control channel information because it must inform the terminal which precoding scheme has been applied.

DL control channel information necessary for SCW MIMO transmission to which precoding is applied should additionally include precoding information as well as the above UE ID, DL RB, TF, and HARQ related information.

Meanwhile, in the case of DCW MIMO transmission to which precoding is applied, since the number of transmission codewords is two, TF and HARQ related information should be transmitted for each codeword. That is, DL control channel information required for DCW MIMO transmission to which precoding is applied includes a UE ID, a DL RB, TF # 1 (TF of the first codeword), TF # 2 (TF of the second codeword), HARQ related information # 1 (HARQ related information of a first codeword), HARQ related information # 2 (HARQ related information of a second codeword), precoding information, and the like.

Here, the precoding information is information indicating which precoding matrix has been applied, and includes a relationship between a layer configured through precoding and a transmission codeword.

Hereinafter, a method of configuring a DL control channel for MIMO transmission to which precoding is applied will be described.

3 illustrates DL control channel information for SCW MIMO to which the present invention is applied.

Referring to FIG. 3, it can be seen that the UE ID 301, the DL RB 303, the precoding information 305, the TF 307, and the HARQ related information 309 are configured. Here, the order of each information is meaningless. If re-transmission time and retransmission, the HARQ-related information 309 may be omitted if the synchronized HARQ that predefine the required resources is applied.

4 illustrates DL control channel information for DCW MIMO to which the present invention is applied.

Referring to FIG. 4, UE ID 401, DL RB 403, precoding information 405, TF # 1 407-1, HARQ related information # 1 409-1, and TF # 2 407. -2), it can be confirmed that the HARQ-related information # 2 (409-2). As in the case of FIG. 3, the order of each information has no meaning, and if the synchronized HARQ is applied, HARQ related information 409-1 and 409-2 may be omitted. That is, as shown in FIG. 4, if the TF and HARQ related information is secured by the number of codewords, DL control channel information for general MCW MIMO can be configured.

In addition, even in a situation where a transmission / reception period is promised to perform DCW MIMO transmission, only one codeword is transmitted if the number of activated layers is one. The technique of adaptively adjusting the number of layers activated according to the state of the MIMO channel is called a hierarchy adaptation (hereinafter, referred to as rank adaptation) technique. If the SINR is low or the channel correlation is high, even though M layers can be configured, the number of layers to which actual signal sequences are transmitted should be set smaller than this. Herein, the layer in which the actual signal sequence is transmitted is called an 'activated layer', and this 'number of layers' is called a transport layer (hereinafter, rank).

DCW MIMO transmission is a method of transmitting two codewords unconditionally when the transmission rank is 2 or more. If the transmission rank is 1, only one codeword can be transmitted. When the rank is 1, the operation of the SCW MIMO and the DCW MIMO coincide with each other. When precoding is applied, this may be regarded as adaptive beamforming.

Meanwhile, among the DL control channel information for DCW MIMO of FIG. 4, TF # 2 407-2 and HARQ related information # 2 409-2 are not necessary when the transmission rank is 1. However, in the conventional mobile communication system, even in rank-1 transmission of DCW MIMO, the TF # 2 (407-2) and HARQ related information # 2 (409-2), that is, have a channel structure that transmits unnecessary information. There was a problem.

Therefore, there is a need for defining a structure of a downlink control channel for DCW MIMO according to rank in a MIMO system.

Accordingly, the present invention devised to solve the problems of the prior art operating as described above provides an apparatus and method for transmitting and receiving a downlink common control channel in a packet data mobile communication system.

In addition, the present invention provides an apparatus and method for configuring and transmitting a downlink common control channel in a mobile communication system having a plurality of antennas for transmitting packet data.

In addition, the present invention provides an apparatus and method for configuring a downlink common control channel in a MIMO system for adaptively controlling a transport layer (Rank).

The present invention also provides an apparatus and method for transmitting / receiving a downlink control channel configured by optimizing the amount of control channel information for a double codeword (DCW MIMO) according to a rank in a MIMO system to which the Rank adaptation scheme is applied.

The present invention relates to a method of transmitting a packet using multiple antennas in a mobile communication system, wherein the first precoding information indicating whether the packet is precoded using one encoding codeword, or is distinguished from at least one or more packets. Generating a control channel by selectively including one of second pre-coding information indicating whether the packet is pre-encoded using encoded codewords, and mapping the generated control channel to a resource block to transmit to a specific receiving device Characterized by including the process.

The present invention relates to a method for transmitting a packet using multiple antennas in a mobile communication system, the method comprising: generating a control channel including extended control information indicating whether the packet is pre-coded through at least one or more encoded codewords; And transmitting the generated control channel to a specific receiving device through a resource block.

According to the present invention, a method for receiving a packet transmitted through multiple antennas in a mobile communication system includes receiving a first control channel including first precoding information indicating whether the packet is precoded through one coded codeword. Detecting an error and confirming that an error does not occur in the first control channel, checking resource block information of the first control channel and receiving a packet transmitted through the determined resource block; Decoding the received packet using the one coded codeword, and if it is determined that an error occurs in the first control channel, pre-packaging the packet by using at least one distinguished coded codeword. Error detection by receiving a second control channel including second precoding information indicating whether an encoding has been performed. And if it is confirmed that no error occurs in the second control channel, checking resource block information of the second control channel, receiving a packet transmitted through the determined resource block, and receiving the received packet. And distinguishing the data using the at least one encoded codeword.

The present invention relates to a method for receiving a packet transmitted through multiple antennas in a mobile communication system, comprising extended control information indicating whether the packet is pre-coded through at least one or more coded codewords, and pre-coding the packet. Receiving a first control channel including information; and receiving a second control channel including different second precoding information, which is different from the first control channel according to the presence or absence of the extended information. It is characterized by including.

The present invention relates to an apparatus for transmitting a packet using multiple antennas, comprising: a scheduler for selecting a specific resource block to transmit a control channel for the packet, and indicating whether the packet is pre-encoded using the one coded codeword. A control channel generator for generating a control channel selectively including one of first precoding information and second precoding information indicating whether the packet is precoded using at least one or more distinct coded codewords, and the scheduler; It characterized in that it comprises a mapper for mapping the generated control channel to the particular resource block selected.

The present invention relates to an apparatus for receiving a packet, comprising: extended control information indicating whether the packet has been pre-coded through at least one or more coded codewords, the first pre-coding information for the packet; A control channel receiver for receiving a control channel or receiving a second control channel including different second precoding information different from the first control channel according to the presence or absence of the extended information; and the received first A reception coupling coefficient calculator for obtaining a reception coupling coefficient using the first precoding information or the second precoding information acquired from a control channel or a second control channel, and according to the reception coupling coefficient received from the reception coupling coefficient calculator. And a data processing unit for decoding the packet transmitted in the specific resource block to obtain the transmission data. It is gong.

The operation principle of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The present invention proposes a method for transmitting and receiving a downlink (DL) common control channel in a mobile communication system for transmitting packet data. Particularly, the present invention provides a DCW MIMO according to a set rank in a MIMO system to which an adaptive rank technique is applied. We propose a method of configuring a control channel by optimizing the amount of DL control channel information.

According to the present invention, although the TF # 2 and the HARQ-related information # 2 are not needed when rank-1 transmission, that is, only one codeword is transmitted in the conventional DCW MIMO, resources secured by considering two or more rank transmissions In order to solve the conventional problem of consuming the above, we propose a method of configuring a DL control channel for DCW MIMO using the necessary resources according to the transmission rank.

<First Embodiment>

First, FIG. 5 illustrates DL control channel information for DCW MIMO assuming blind detection proposed in the first embodiment of the present invention. Here, the blind detection means that the base station can transmit DL control channel information using one of a plurality of DL control channel information formats, and the terminal receives without prior information on which format of DL control channel information is to be transmitted. It means.

Referring to FIG. 5, a DL control channel format 510 for DCW MIMO for rank-1 transmission and a DL control channel format 520 for DCW MIMO for rank-2 or higher transmission is shown. That is, 510 is a format used when one codeword is transmitted and 520 is a format used when two codewords are transmitted. In this case, the terminal does not know which of two formats according to the rank transmission is transmitted DL control channel.

Therefore, the terminal should try to receive both formats. The disadvantage of blind detection in this regard is that the receiver complexity increases in that the receiver must attempt to receive in different formats. However, the advantage of DL control channel transmission assuming blind detection is that resource consumption is optimized for each format.

In other words, the format 510 used when one codeword is transmitted is a UE ID 501, a DL RB 503, precoding information 505 for rank-1 transmission, and TF # 1 507-1. And HARQ related information # 1 509-1.

The precoding codebook lists all possible precoding methods and indexes them, and is used as a guide for indicating which precoding method is requested or applied in the feedback or DL control channel.

For example, assuming that all of the C precoding methods are defined in the precoding codebook, C ₁ precoding methods are dedicated to rank-1 transmission, and the remaining (CC ₁ ) precoding methods are rank-2 or more. Is for transfer only.

비트가 필요하다. 여기서

는 올림 연산자이다.Thus, the pre-coding information for the rank-1 transmission formats 510, 505 in order to refer to a representation of one of the C ₁ rank-1 transmission-only pre-coding

I need a bit. here

Is the rounding operator.

Meanwhile, the format 520 used when two codewords are transmitted is a UE ID 501, a DL RB 503, pre-coding information 511 for rank-2 or higher transmission, and TF # 1 507-1. , HARQ related information # 1 509-1, TF # 2 507-2, and HARQ related information # 2 509-2.

비트가 필요하다. Here, the pre-coding information 511 for rank-2 or higher transmission refers to one of (CC ₁ ) rank-2 or higher transmission-only precoding.

I need a bit.

비트가 필요했다면, 상기 도 5의 사전부호화 정보(511) 구조에서 가장 많은 정보량을 소비하는 경우는 코드워드가 두 개 전송될 경우 사용하는 포맷(520)이다. For reference, the precoding information 405 of FIG. 4 is used to refer to one of the C precoding.

If a bit was needed, the largest amount of information consumed in the precoding information 511 structure of FIG. 5 is a format 520 used when two codewords are transmitted.

이므로, 도 5의 정보는 도 4의 정보와 비교할 때 동일한 정보량이 필요하거나 혹은 적은 정보량이 필요하다는 것을 확인할 수 있다.That is necessary

Therefore, the information of FIG. 5 may confirm that the same amount of information or a smaller amount of information is required when compared with the information of FIG. 4.

Accordingly, according to the present invention, with the same or less amount of information, indicating the transmission of rank-1 transmission or rank-2 transmission in DCW MIMO, the receiver provides the advantage of simplifying the reception complexity.

6 is a flowchart illustrating reception of DL control channel information for DCW MIMO assuming blind detection proposed in the present invention.

Referring to FIG. 6, when a terminal starts 601 a DL control reception signal, it attempts to receive a first DL control signal from a specific DL control signal resource block (RB) (603). Here, RB represents one subcarrier group, and the RB is composed of X consecutive subcarriers and Y consecutive OFDM symbols, and the size thereof is X * Y.

In addition, as shown in FIG. 5, the first DL control signal is a DL control signal of a format 510 used when one codeword is transmitted. Thereafter, the terminal determines whether the first DL control signal has been successfully received through the CRC check (605). If the terminal has successfully received the terminal, the terminal starts receiving data from the DL RB allocated to the terminal (607). )do.

Meanwhile, if the first DL control signal is not successfully received, the terminal attempts to receive the second DL control signal (609). The second DL control signal is a DL control signal of a format 520 used when two codewords shown in FIG. 5 are transmitted. That is, in the present invention, since the DL control signal is designed assuming blind detection, it attempts to receive the first DL control signal and fails to receive the second DL control signal.

Next, it is determined whether the second DL control signal has been successfully received through the CRC check (611). If the reception is successful, the reception of data is started 607 in the DL RB allocated to the terminal based on this information.

On the other hand, if not, the process moves to another DL control signal RB (613) and repeats the above procedure from the attempt 603 to receive the first DL control signal.

Accordingly, according to the present invention, when only one codeword is transmitted in the blind detection-based scheme, the sub-codebook includes only pre-coding only for rank-1 transmission among pre-coding information. In the case of two codewords being transmitted, the pre-encoding information is represented using the element index of the sub-codebook consisting of only the pre-coding of rank-2 or more, so that unnecessary resource consumption can be prevented. Has

<< 2nd Example >>

FIG. 7 illustrates DL control channel information for DCW MIMO assuming separate coding proposed in the second embodiment of the present invention.

Assuming separate encoding, the terminal first receives control information 710 (hereinafter, referred to as a first DL control signal) for restoring the first codeword, and expands control information for restoring the second codeword through the control information. 720, the second DL control signal (hereinafter referred to as “second DL control signal”) may be used after receiving the extended control information. Accordingly, the terminal can reduce the complexity of the control channel reception as compared with the blind detection.

Referring to FIG. 7, the first DL control signal 710 is UE ID 711, DL RB 703, extension information 713, and precoding information part 1 (control information for restoring the first codeword). 715), TF # 1 707-1, and HARQ related information # 1 709-1. When only one codeword is transmitted, data can be received using only the information of the first DL control signal 710.

The second DL control signal 720 includes a UE ID 717, precoding information part 2 719, TF # 2 707-2, and HARQ related information # 2 (control information for restoring the second codeword). 709-2). When two codewords are transmitted, not only the first DL control signal 710 but also information of the second DL control signal 720 is required for data reception.

That is, the transmitting apparatus may know whether only one codeword is transmitted or two are transmitted through the extended information 713. If only one codeword is transmitted, the extension information will indicate that the reception of the second DL control signal is not needed (no extension information). If two codewords are transmitted, the extension information will indicate that the reception of the second DL control signal is not received. You will be told that it is necessary (with extension information).

비트가 필요하다. In addition, when there is no extension information, precoding information part 1 indicates precoding information for rank-1 transmission. This is to express that, as described in the example of blind detection, precoding information part 1 refers to one of C ₁ rank-1 transmission only precoding.

I need a bit.

비트가 할당되어 있고,(C-C₁)개의 rank-2 이상 전송 전용 사정부호화 중 하나를 지칭하는 것을 표현하기 위해

비트가 필요하므로 사전부호화 정보 파트2로

비트가 필요하다. On the other hand, when there is extended information, the precoding information part 1 and the ejaculation encoding information part 2 collectively represent one of rank-2 or more transmission-only precoding. Already into Precoding Information Part 1

Bit to be allocated and to represent one of (CC ₁ ) rank-2 or more transmission-only ejaculation encodings.

Bits are required, so the precoding information

I need a bit.

That is, based on the extended information, the precoding information part 1 is used as rank-1 transmission-only precoding information when there is no extension information, and when there is extension information, it is used as part of rank-2 or higher transmission-only precoding information. The remaining information is obtained from precoding information part 2.

For example, precoding information part 1 is 2 bits, precoding information part 2 is 3 bits, and rank-2 or higher transfer only precoding information is 2 bits for precoding information part 1 (Most Significant Bit, MSB) is assumed to be represented by a total of 5 bits of 3 bits for the Least Significant Bit (LSB) for the precoding information part 2.

If the information 01 is recorded in the precoding information part 1, it means that the precoding with index 01 is used among rank-1 transmission-only precoding. In the case of the extension, if the information 111 is additionally received by receiving the pre-coding information part 2, the transmission-only pre-coding information of rank-2 or more may be interpreted as the information 01111. This means that you are using precoding with an index of 01111.

On the other hand, if the second DL control signal 720 includes a UE ID 717, and this UE ID is inserted in the form of a CRC, the CRC # 2 indicates the UE ID (the ID of the first DL control signal 710). Only the number of bits smaller than CRC # 1 of 711 may be used or omitted. This configuration is a measure for reducing or eliminating the disadvantage that the separate coding scheme additionally consumes resources for CRC # 2.

In addition, this is because the bits of the CRC # 2 can be reduced if the events in which the reception error of the first DL control signal 710 and the second DL control signal 720 occur are not independent of each other.

8 is a flowchart illustrating reception of DL control channel information for DCW MIMO assuming separate coding proposed in the present invention.

Referring to FIG. 8, when the terminal starts 801 the DL control reception signal, the terminal attempts to receive the first DL control signal from the first DL control signal RB (803). The CRC # 1 check determines whether the first DL control signal has been successfully received (805). If successful, it is determined whether there is an extension based on the extension information, that is, whether there is an additional second DL control signal. Decision 809 is made.

On the other hand, if the first DL control signal has not been successfully received through the CRC # 1 check, it moves to another control signal RB 807 and starts again from the reception attempt 803 of the first DL control signal.

If it is determined in step 809 that there is no extension information, the precoding information part 1 recognizes which rank-1 transmission-only precoding scheme is used (811) and starts receiving data in the allocated DL RB (813). do.

On the other hand, if it is determined in step 809 that there is extended information, the second DL control signal is attempted to be received (815). If CRC # 2 is defined, it is determined whether the second DL control signal has been successfully received through the CRC # 2 check (817). In this case, if the second DL control signal is successfully received, the precoding information part 1 of the first DL control signal received in step 803 and the precoding information part 2 of the second DL control signal received in step 815 are combined. It recognizes (819) which is used in a rank-2 or higher transfer-only precoding scheme. Thereafter, data reception is started at the allocated DL RB (813).

If the second DL control signal has not been successfully received in step 817, the controller 100 moves to another control signal RB 807 and starts again from the attempt 803 of receiving the first DL control signal.

Accordingly, in the present invention according to the second embodiment, when only one codeword is transmitted in a distinctive encoding-based scheme, the precoding information part 1 includes an element index of the subcodebook including only rank-1 transmission-only precoding. When two codewords are transmitted, this indicates an element index of a subcodebook including only rank-2 or higher transmission-only precoding, in which precoding information parts 1 and 2 are combined.

9 shows a configuration diagram of a transmission device according to the present invention.

Referring to FIG. 9, which RB is to be transmitted is determined by the scheduler 901. The scheduler 901 selects an RB suitable for transmission based on the received, interpreted, and transmitted information related to the channel state of each user among the signals fed back from the feedback receiver 910. In this case, the feedback receiver 910 receives the feedback information related to the precoding and transmits the feedback information to the precoding method determiner 911. The TF determiner 913 determines the TF for each signal sequence based on the determined precoding scheme and the channel state.

The demultiplexer 902 demultiplexes each user information signal for DCW MIMO transmission. Each demultiplexed signal sequence undergoes individual channel encoding and modulation (903-1, 903-2) according to DCW MIMO transmission. Here, channel encoding and modulation are performed according to the command determined by the TF determiner 913. In addition, the modulated signal sequence is pre-coded through the pre-coder 904 commanded by the pre-coding scheme determiner 911, and the pre-coded signal sequence is determined by the scheduler 901 through the symbol-resource mapper 905. Is placed on.

Meanwhile, the downlink common control channel signal generator 914 generates a control signal based on the identifier of the receiving terminal selected by the scheduler 901, the allocated RB, the precoding scheme used, the TF, and the like. The control channel signal generator 914 constitutes a control channel according to the method proposed in the first and second embodiments of the present invention.

That is, according to the first embodiment of the present invention, the control channel signal generator 914 may include first precoding information indicating whether the user bit stream to be transmitted is precoded using one coded codeword, or at least one or more bits. A control channel is configured by selecting one piece of encoding information from second precoding information indicating whether the packet is pre-encoded using distinguished encoding codewords.

Meanwhile, according to the second embodiment of the present invention, the control channel signal generator 914 generates a control channel including extension information indicating whether the packet is pre-coded through at least one or more coded codewords. That is, the control channel signal generator 914 includes a first control including the extension information indicating whether the packet is pre-coded using the at least one coded codeword and the first precoding information that pre-codes the packet. Create a channel. A second control channel including second precoding information different from the first encoding information is configured with respect to the extension information.

The symbol-resource mapper 905 maps the control signal and the pre-coded discrimination sequence constructed according to the first and second embodiments of the present invention to the allocated specific resources. The signals mapped to the specific transmission resources are transmitted to the multiple transmission antennas 907a and 907m through the transmission processors 906a and 906m.

10 is a block diagram of a receiving apparatus according to the present invention.

Referring to FIG. 10, a signal received by the multiple reception antennas 1001a and 1001n receives a data signal and a control signal through the reception processors 1002a and 1002n.

The downlink common control channel signal receiver 1010 receives control signals generated according to the first and second embodiments of the present invention and restores control information such as precoding information and TF. That is, according to the first embodiment, the downlink common control channel signal receiver 1010 checks the CRC with respect to the received first DL control signal, and receives the data signal if it is normally received. At this time, if the first DL control signal is not normally received, the second DL control signal is received.

At this time, whether the first DL control signal or the second DL control signal with respect to the received control signal can be confirmed through the precoding information of the control signal. Meanwhile, according to the second embodiment, it is determined whether the pre-coding information part 2 of the second DL control signal should be further received through the received extension information of the first DL control signal.

The reception coupling coefficient calculator 1011 obtains a reception coupling coefficient based on the recovered precoding information and the reception channel state, and passes the result to the reception combiner 1003 to restore the DCW MIMO transmission signal sequence.

The TF determiner 1012 passes the received TF information to demodulation and channel decoding 1004. The demodulation and channel decoding 1004 performs demodulation and channel decoding on the received data signal using the transferred TF information.

The interference canceller 1005 is to improve reception performance. When the data stream is successfully restored through the demodulation and channel decoding 1004, the interference canceller 1005 removes interference on the restored signal. In this case, the interference canceller 1005 performs demodulation and channel decoding 1004 and repeats the interference cancellation, demodulation, and channel decoding until all interferences contributed by the signal sequence are first restored in order of the restored signal sequence. .

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, and equivalents thereof.

In the present invention that operates as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention has the advantage of constituting a DL control channel for DCW MIMO by consuming the necessary transmission resources according to the transmission rank in suggesting a blind detection-based scheme and a separate encoding-based scheme in a MIMO system. In addition, there is an advantage of optimizing the amount of control information included in the control channel configuration.

Therefore, in the configuration of the downlink control channel, when at least one or more codewords are used, an unnecessary resource consumption can be prevented when configuring the control channel using the codeword.

Claims (24)

A method of transmitting a data downlink common control channel including a control signal necessary for restoring the transmitted data signal in a mobile communication system transmitting a data signal using multiple antennas, the method comprising: Determining whether the transmitted data signal is encoded by transmitting two or more code words, and According to the determination result, one of a first element index of a sub-codebook consisting of only one codeword-only precoding of one of the precoding codebooks or a second element index of a subcodebook consisting of only two or more codeword-only precodings. Selecting the process, Generating a control channel by including the selected element index as the precoding information; And mapping the generated control channel to a specific resource block and transmitting the mapped control channel to a specific receiving device. The method of claim 1, The control channel is When the transmitted data signal is encoded and transmitted in one code word, Downlink common control, characterized in that it further includes identifier information of the specific receiving apparatus, downlink resource block information for transmitting a packet, transmission format information (TF) of the packet, and information indicating the number of retransmissions of the packet. Channel transmission method. The method of claim 1, The number of bits required to express the first element index is expressed by Equation 1 below. &Quot; (1) &quot; One codeword only bit =

In Equation (1)

Is the rounding operator, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword-only pre-coding. The method of claim 1, The downlink common control channel is When the transmitted data signal is encoded and transmitted in two or more code words, identifier information of the specific receiver, downlink resource block information for transmitting a packet, and two or more packets corresponding to the respective code words are transmitted. And downlink transmission control information (TF) and information indicating the number of two or more packet retransmissions corresponding to the respective codewords. The method of claim 1, The number of bits required to express the second element index is expressed by Equation 2 below. &Quot; (2) &quot; 2 or more codeword only bits =

In Equation (1)

Is the rounding operator, C is the number of elements of the pre-encoded codebook consisting of all possible pre-coding, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword only pre-coding. The method of claim 1, The process of generating the control channel When the transmitted data signal is encoded and transmitted in two or more code words, a first downlink common control channel and a second precoded information part including a control signal corresponding to the first precoded information part and the first codeword. Generate all of the second downlink common control channels including the control signals corresponding to the second code words; And the first downlink common control channel further includes extension information indicating that there is a control signal to be transmitted through the second control channel. The method according to claim 6, The process of generating the control channel And combining the first precoded part and the second precoded part to represent the second element index. 8. The method of claim 7, The number of bits required in the second pre-coding part is calculated by Equation (3) below. &Quot; (3) &quot; Number of second pre-coded parts =

In Equation (3)

Is the rounding operator, C is the number of elements of the pre-encoded codebook consisting of all possible pre-coding, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword only pre-coding. A method for receiving a downlink common control channel including a control signal for restoring the data signal in a mobile communication system transmitting a data signal using multiple antennas, the method comprising: Receiving a first control channel for a data signal encoded with one code word or a second control channel for a data signal encoded with two or more code words and detecting an error; Detecting control information included in a control channel which has been successfully received as a result of the error detection; And receiving and decoding data in a downlink resource block allocated to the terminal based on the detected control information. 10. The method of claim 9, The process of detecting the control information When the first control channel is successfully received, the pre-coding information included in the first control channel is recognized as a first element index of a sub-codebook composed of only one codeword-only precoding. A downlink common control channel reception method. 10. The method of claim 9, The process of detecting the control information When the second control channel is successfully received, the pre-coding information included in the second control channel is recognized as a second element index of a sub-codebook consisting of only two or more codeword-only precodings. A downlink common control channel reception method. A method for receiving a downlink common control channel including control information for restoring the data signal in a mobile communication system transmitting a data signal using multiple antennas, the method comprising: Receiving a first control channel for a data signal, Determining whether the first control channel includes extension information indicating whether the first control channel includes control information on data encoded with two or more code words; Detecting extended control information included in the first control channel when the extended control information is not included in the first control channel; And receiving data from a downlink resource block allocated to the terminal based on the detected control information and decoding the data using one code word. 13. The method of claim 12, The process of detecting the control information When the first control channel is successfully received, the first element index of a sub-codebook consisting of only one codeword-only precoding of information included in the first precoding part included in the first control channel. Downlink common control channel reception method, characterized in that the recognition. 13. The method of claim 12, When the first control channel includes extension information, receiving a second control channel; Detecting control information included in the first control channel and the second control channel; And receiving data from a downlink resource block allocated to the terminal based on the detected control information and decoding the data using two or more code words. 15. The method of claim 14, The process of detecting the control information A second element of a sub-codebook consisting of only two or more codeword-only pre-codings of information combining the first pre-coding part included in the first control channel and the second pre-coding part included in the second control channel. A method for receiving a downlink common control channel, characterized in that it is recognized as an index. An apparatus for transmitting a packet using multiple antennas in a mobile communication system, A scheduler for selecting a specific resource block to transmit a control channel for the packet; It is determined whether the transmitted data signal is encoded by two or more codewords, and the first element index of the sub-codebook consisting of only one codeword precoding of one of the precoding codebooks or two or more codewords only. A control channel generator for selecting one of the second element indices of the sub-codebook composed only of precoding and generating the control channel by including the selected element indices as the precoding information; And a mapper for mapping the generated control channel to the specific resource block selected by the scheduler. 17. The method of claim 16, The control channel generator And the number of bits required to represent the first element index is expressed by Equation 4 below. &Quot; (4) &quot; One codeword only bit =

In Equation (4)

Is the rounding operator, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword-only pre-coding. 17. The method of claim 16, The control channel generator And the number of bits required to express the second element index is expressed by Equation 5 below. &Quot; (5) &quot; 2 or more codeword only bits =

In Equation 5 above

Is the rounding operator, C is the number of elements of the pre-encoded codebook consisting of all possible pre-coding, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword only pre-coding. 17. The method of claim 16, The control channel generator When the transmitted data signal is encoded and transmitted in two or more code words, a first downlink common control channel and a second precoded information part including a control signal corresponding to the first precoded information part and the first codeword. And generating all the second downlink common control channels including the control signal corresponding to the second code word, wherein the first downlink common control channel indicates that there is a control signal to be transmitted through the second control channel. Packet transmission apparatus further comprises. The method of claim 19, The control channel generator And the first pre-coding part and the second pre-coding part are combined to represent the second element index. 21. The method of claim 20, The control channel generator And a number of bits required by the second pre-coding part is expressed by Equation (6) below. &Quot; (6) &quot; Number of second pre-coded parts =

In Equation (3)

Is the rounding operator, C is the number of elements of the pre-encoded codebook consisting of all possible pre-coding, and C ₁ is the number of elements of the sub-codebook consisting of only one codeword only pre-coding. An apparatus for receiving a packet using multiple antennas in a mobile communication system, Expansion control information indicating whether the packet is pre-coded through at least one encoding codeword, and receiving a first control channel including first precoding information for the packet, or whether the extension information is present or not. A control channel receiver for receiving a second control channel comprising different second precoding information, the second control channel being different from the first control channel; A reception coupling coefficient calculator for acquiring a reception coupling coefficient using the first precoding information or the second precoding information obtained from the first control channel or the second control channel; And a data processing unit which decodes a packet transmitted in a specific resource block and obtains transmission data according to the reception coupling coefficient received from the reception coupling coefficient calculator. 23. The method of claim 22, The control channel receiver, Confirming the presence of the extended information so that the reception coupling coefficient calculator combines the precoding information of the first control channel and the second control channel to generate an encoded codeword for decoding the packet. Packet receiving device. 23. The method of claim 22, The data processing unit, Identifier information of a specific receiving device that receives the packet included in the first control channel or the second control channel from the control channel receiver, information about the specific resource block to which the packet is transmitted, and transmission of the packet And decodes the packet by using format information (TF) and information indicating the number of retransmissions of the packet and using the generated coded codeword.

Images