BRPI0806330A2 - layer mapping method and minimum system data transmission method - Google Patents

Abstract

LAYER MAPPING METHOD AND DATA TRANSMISSION METHOD FOR MIMO SYSTEM. A method is disclosed to indicate a combination of a code key and a layer in a MIMO communication system, a layer mapping method and a data transmission method using the same. A minimum number of key code - layer mapping combinations between all available combinations based on the numbers of all code keys and all layers is predefined in consideration of a ratio of one code key to one layer, from performance of receiving a receiver, and reducing combinations, so that a data transmission method that uses predefined combinations is implemented. If a specific code key is mapped to at least two layers, a gain in diversity can be gained.

Description

"LAYER MAPPING METHOD AND DATA TRANSMISSION METHOD FOR MIMO SYSTEM"

Technical Field

The present invention relates to a Multitrack and Multisource communication system (MIMO) and more particularly to a method of displaying a combination of a code key and a layer in a MIMO communication system, a mapping method. layer and a data transmission method using the same.

Background of the Invention

Conventional MIMO technology will be described in detail below.

In short, MIMO technology is an abbreviation for Multi-Input and Multi-Output technology. MIMO technology uses multiple transmit antennas (Tx) and multiple receive antennas (Rx) to improve Tx / Rx data efficiency, whereas conventional technology generally uses a single transmit antenna (Tx) and a single receiving antenna (Rx). In other words, MIMO technology allows a transmitter or receiver of a wireless communication system to use multiple antennas (hereafter referred to as multi-antennas) so that capacity or performance can be improved. For convenience of description, the term "MIMO" may also be considered a multi-antenna technology.

In more detail, MIMO technology does not rely on a single antenna path to receive a single total message, it collects a plurality of pieces of data received through multiple antennas, and completes total data. As a result, MIMO technology may increase a data rate under a given channel condition, or may increase system performance at a specific data rate.

Next-generation mobile communication technology requires faster data transmission speeds than conventional mobile communication technology, so effective MIMO technology is expected to be a requirement for mobile communication technology. of the next generation. In this situation, MIMO communication technology is the next generation mobile communication technology that can be applied to mobile communication terminals or base stations, and can extend the range of a data communication range, so that it can overcome the limited amount of transfer data from other mobile communication systems due to a variety of limited situations.

Among a variety of technologies that can improve data transmission efficiency, MIMO technology can greatly increase the amount of communication capacity and Tx / Rx performances without allocating additional frequencies or increasing additional power. Because of these technical advantages, most companies or developers have been paying close attention to this MIMO technology.

Figure 1 is a block diagram illustrating a conventional MIMO communication system.

Referring to Figure 1, if the number of transmit antennas (Tx) increases to Nt and at the same time the number of receive antennas (Rx) increases to Nr, a theoretical channel capacity of the MIMO communication system. it increases in proportion to the number of antennas, so that a transmission speed and frequency efficiency can increase enormously.

In this case, the transmission speed acquired by the higher channel capacity is equal to the multiplication of a maximum transmission speed (Ro), acquired when a single antenna is used, by an increase in speed (Ri) and, theoretically, can increase. lie. The increase in velocity (Ri) can be represented by the following equation 1:

Equation 1

Ri = min (NT, Nr)

For example, as long as the MIMO system uses four Tx antennas and four Rx1 antennas theoretically, this MIMO system can achieve a high transmission speed, which is four times higher than that of a single antenna system.

After the aforementioned theoretical increase in capacity of the MIMO system was demonstrated in the mid-1990s, many developers are conducting intensive research on a variety of technologies that can substantially increase a data transmission rate using theoretical capacity increase. Some of them reflected in a variety of wireless communication standards, for example, third generation mobile communication or next generation wireless LAN, etc.

A variety of MIMO-associated technologies have been intensively researched by many companies or developers, for example, research into an information theory associated with a calculation of MIMO communication capabilities in various channel environments or multi-access environments, research. in a wireless channel measurement and modeling of the MIMO system, and research into a space - time signal processing technology.

The aforementioned MIMO technology can be classified into two types: a spatial diversity scheme and a spatial multiplexing scheme. The spatial diversity scheme increases transmission reliability by using symbols that pass in various channel paths. The spatial multiplexing scheme simultaneously transmits a plurality of data symbols via a plurality of Tx antennas, so that it increases a data transmission rate. Moreover, the combination of the spatial diversity scheme and the spatial multiplexing scheme has also recently been developed to appropriately acquire unique advantages of the two schemes.

Details of the spatial diversity scheme, spatial multiplexing scheme and their combination will be described below.

First, the spatial diversity scheme will be described next. In general, the spatial diversity scheme is divided into two types: a space-time block code scheme and a space-time Trellis code scheme, which can simultaneously use a diversity gain and a coding gain. . Overall, a performance with improved bit error rate (BER) and a degree of freedom of code generation from the space-time Trellis code scheme are superior to those of the space block code scheme - time, while the complexity of calculating the space - time block code scheme is greater than that of the space - time Trellis code scheme.

The aforementioned gain in spatial diversity corresponds to the product or multiplication of the number (Nt) of Tx antennas by the number (Nr) of Rx1 antennas as denoted by Nt X Nr.

Secondly, the spatial multiplexing scheme will be described below. The spatial multiplexing scheme is adapted to transmit different continuous streams of data through individual Tx antennas. In this case, a receiver may inevitably generate mutual interference between simultaneously transmitted pieces of data from a transmitter. The receiver removes this mutual interference from the received data using an appropriate signal processing technique so that it can receive the desired data without interference. In order to remove noise or interference from the received data, a maximum probability receiver, ZF (Zero Forcing) receiver, MMSE (Minimum Mean Square Error) receiver, D-BLAST or V-BLAST can be used. Specifically, if a transmitter can recognize channel information, a Singular Value Decomposition (SVD) scheme can be used to perfectly remove the interference.

Third, the combination of the spatial diversity scheme and the spatial multiplexing scheme will be described below. As long as only one gain in spatial diversity is acquired, the performance improvement gain is gradually matched in proportion to an increasing order of diversity. As a result, a variety of schemes that can acquire both of the above gains simultaneously, while still solving the above problems, have been intensively researched by many companies or developers, for example a double STTD scheme and a space-time BICM scheme. (STBICM).

A mathematical modeling of a communication method for use in the aforementioned MIMO system will be described in detail below.

First, as can be seen from Figure 1, it is considered that there are Nt Tx antennas and Nr Rx antennas.

In the case of a transmission signal (Tx) 1 a maximum number of transmission information pieces is NT under the condition that NT Tx antennas are used, so that signal Tx can be represented by a specific vector shown in the following. equation 2:

Equation 2

S = [Si, S2, ..., Snt] t

Individual transmission information pieces (S1, S2 ..... sNT) may have different transmission energies. In this case, if the individual transmission energies are denoted by (P1, P2, ..., Pnt)> the transmission information with an adjusted transmission energy can be represented by a specific vector shown in the following equation 3:

Equation 3

S = Js1,4, · "Jj = [p151, p252} -, JpWrsWF] r

In equation 3, using a diagonal matrix of a transmission energy Ρ,

can be represented by the following equation 4:

Equation 4

<formula> formula see original document page 5 </formula>

The information vector with an adjusted transmission energy is multiplied by a weighting matrix (W) 1 so that Nt transmission signals (Tx) (χΊ, x2l ..., Xnt) are actually configured. In this case, the weighting matrix is adapted to properly distribute Tx information to individual antennas according to Tx channel situations. The above signals Tx (X1, x2 ..... xNT) can be represented by the following equation 5 using the vector (x):

Equation 5

<formula> formula see original document page 5 </formula> In equation 5, Wij is a weighting between the ith antenna Tx and the jth information Tx1 and W is a matrix indicating the Wij weighting. The matrix W is called a weighting matrix or a precoding matrix.

The above signal Tx (x) can be considered in different ways according to two cases, that is, a first case in which spatial diversity is used and a second case in which spatial multiplexing is used.

In the case of using spatial multiplexing, different signals are multiplexed, and multiplexed signals are transmitted to a destination, so that elements of the information vector (s) have different values. In other circumstances, if spatial diversity is used, the same signal is repeatedly transmitted over several channel paths so that elements of the information vector (s) have the same value.

Needless to say, the combination of the spatial multiplexing scheme and the spatial diversity scheme can also be considered. In other words, the same signal is transmitted via three Tx antennas according to the spatial diversity scheme, and the remaining signals are spatially multiplexed and then transmitted to a destination.

Next, if Nr Rx antennas are used, Rx signals Cy1, y2, ..., yNR) from individual antennas can be represented by a specific vector (y) shown in the following equation 6:

Equation 6

<formula> formula see original document page 6 </formula>

If a channel modeling is configured in the MIMO communication system, the individual channels can be distinguished from each other according to the Tx / Rx ante indexes. A specific channel from an antenna Tx (j) to an antenna Rx (i) is denoted by hij. In this case, it can be seen that the first index of the channel Kiij indicates an antenna index Rx and the second means an antenna index Tx.

Multiple channels are tied so that they are displayed as a vector or matrix. An exemplary vector is as follows.

Figure 2 shows channels from Nt Tx antennas to an Rx antenna (i).

Referring to Figure 2, the channels from the Nt Tx antennas to the Rx antenna (i) can be represented by the following equation 7:

Equation 7

<formula> formula see original document page 6 </formula>

If all channels from Nt Tx antennas to Nr Rx antennas are denoted by the composite matrix of Equation 7, the following Equation 8 is acquired:

Equation 8 <figure> figure see original document page 7 </figure>

An Additive White Gaussian Noise (AWGN) is added on a real channel that has passed the H channel matrix shown in Equation 8. The AWGN (ni, n2, ..., nNFt) added on each of the Nr Rx antennas can be represented. by a specific vector shown in the following Equation 9:

Equation 9

N = [n1, n2, ..., n "NR] T

By the aforementioned modeling method of signal Tx1 signal Rx1 and channels including AWGN1 each MIMO communication system can be represented by the following

Equation 10:

Equation 10

<figure> figure see original document page 7 </figure>

The above description disclosed that the MIMO communication system is applied to a single user. However, the MIMO communication system can also be applied to multiple users, so that it can acquire multiuser diversity. A detailed description of multiuser diversity will be given below.

The fading channel is a major cause of deteriorating performance of a wireless communication system. A channel gain value changes over time, frequency, and space. The lower the channel gain value, the lower the performance. A representative method for solving the aforementioned fading problem is a diversity. This diversity uses the fact that there is a low probability that all independent channels have low gain values. A variety of diversity methods may be applied to the present invention, and the above-mentioned multiuser diversity is considered one of them.

If multiple users are present in a cell, individual user channel gain values are stochastically independent of each other, so that the probability that all users have low gain values is very low. If a B-Node has sufficient transmit power (Tx) and multiple users are present in one cell, it is preferable that all channels be allocated to a specific user with the highest channel gain value to maximize a total channel capacity according to information theory. Multi-user diversity can be classified into three types of diversity, namely temporal multi-user diversity, frequency multi-user diversity and spatial multi-user diversity.

Temporal multiuser diversity is adapted to allocate a channel to a specific user with the highest channel gain value when a channel situation changes over time.

Multi-user frequency diversity is tailored to allocate one subcarrier (s) to a specific user with the highest gain value in each frequency band in a multi-carrier frequency system, such as a Multiplex system. - Orthogonal Frequency Division (OFDM).

If the situation of a channel changes slowly over time on another non-multiport system, the user with the highest channel gain value will monopolize the channel over a long period of time, and other users cannot communicate with each other. with others. In this case, in order to use multiuser diversity, there is a need to induce the channel to change.

Next, spatial multiuser diversity uses different user channel gain values according to space types. An example of implementing spatial multiuser diversity is a Random Beam Formation (RBF) method. This RBF method performs beam predetermined weighting using multiple antennas (ie, multi-antennas) to induce channel shift, and uses the aforementioned spatial multiuser diversity.

The multiuser MIMO scheme that uses multiuser diversity as the multi-array scheme will be described in detail below.

According to the multiuser multi-user scheme, the number of users and the number of antennas of each user can be combined with each other in various ways in the transmission / receivers.

The multiuser MIMO scheme is classified into a downlink method (ie a direct link method) and an uplink method (ie a reverse link method), and detailed descriptions of the downlink and uplink links will be made next. In this case, the downlink indicates that a signal is transmitted from one Node-B to several user equipment (UEs), and the uplink indicates that several UEs transmit a signal to the Node-B. In general, downlink in MIMO can be categorized into two types of signal reception methods: the first reception method enables a single user (ie, a single UE) to receive a desired signal through a total of Nr. antennas, and the second receive method enables each of the Nr UEs to receive a desired signal via a single antenna. If required, a combination of the first and second reception methods may also be made available for the present invention. In other words, some UEs may use a single Rx1 antenna or some UEs may use three Rx antennas. It is noticed that a total number of Rx antennas in all combinations is kept at Nr. In general, this case is called a MIMO Broadcast Channel (BC) or a Space Division Multiple Access (SDMA). .

MIMO uplink can generally be classified into two types of signal transmission methods. The first transmission method enables a single UE to transmit a desired signal via Nt antennas, and the second transmission method enables each of the Nt UEs to transmit a desired signal via a single antenna. If required, a combination of the first and second transmission methods may also be made available for the present invention. In other words, some UEs may use a single Tx antenna, or some other UEs may use three Tx antennas. It is noticed that a total number of Tx antennas in all combinations is kept in NT. In general, this case is called a MIMO Multiple Access Channel (MAC).

The uplink and downlink are symmetrical with respect to each other, so that a method for use in one can also be used for the other.

For convenience of description and better understanding of the present invention, although the following description basically describes BC MIMO, it is understood that the method of the present invention is also used for MAC MIMO.

Figure 3A is a conceptual diagram illustrating a single user MIMO communication system. Figure 3B is a conceptual diagram illustrating a multiuser MIMO communication system.

For convenience of description, Figures 3A and 3B assume the use of a downlink.

The single-user MIMO communication system shown in Figure 3A includes a transmitter (i.e. Node-B) equipped with multiple antennas (i.e. multi-antennas) and a receiver (i.e. UE) equipped with multiple antennas. In this case, if a signal (x) to be transmitted from the transmitter is multiplied by a weighting vector (W), and the resulting multiplied signal is transmitted by multi-antenna, the present invention may acquire a maximum channel capacity. considering that the channel information has been correctly recognized.

In the meantime, the multi-user MIMO communication system shown in Figure 3Β includes a plurality of Multiple Input and Single Output (MISO) systems, each of which assigns a single antenna to each user. Therefore, multiusers can maximize channel capacity by using a transmission beam formation in the same way as in the single-user MIMO communication system. In this case, the multi-user MIMO communication system must consider not only channel information but also interference from each user, so that it requires a more complicated system than that of the single user MIMO communication system. Therefore, the multiuser MIMO communication system should select a weighting vector to minimize interference between users in the case of transmission beam formation.

The above description may be numerically described as follows.

First, the single user environment, that is, the single user MIMO communication system, will be described next.

As long as every transmission / receiver has fully recognized all channel information, a singular value decomposition (SVD) H can be represented by the following Equation 11:

H = UΣVh

where "H" is a singular value decomposition, UeV is a unit matrix, and Σ is a diagonal matrix.

In this case, in order to acquire a maximum gain in light of the channel capacity, the diagonal matrix V is selected by the weighting matrix W, and Uh is multiplied by a receive signal (Y). If the resulting signal from the receiver is denoted by y, the following Equation 12 is acquired:

Equation 12

W = V

y = Hx + n = UΣVHx + n = UΣHVWs + n = UΣVHVs + n = UΣs + n

y = UHy = UHUΣs + UHn = +s + n = ΣPs + n

where P is a transmission energy matrix. The transmission energy matrix P can be determined by a specific algorithm (well-known as a water-filling algorithm) to acquire channel capacity. This water-filling algorithm is an ideal method for acquiring channel capacity.

However, in order to perform the water-filling algorithm, all transmitters / receivers must know all channel information completely. Therefore, in order to use the water-filling algorithm in the multiuser environment, each user must know not only their channel information, but also the channel information of other users. Because of this problem, in fact, it is almost impossible for the multi-user MIMO communication system to use the above-mentioned water-filling algorithm.

Next, the multi-user MIMO communication system will be described.

In this case, a representative ideal method for acquiring channel capacity is a Dirty Paper Encoding (DPC) 1 method but this DPC method has high complexity. Also, there are other ideal methods for use in the present invention, for example, Random Beam Formation (RBF) and Zero Forced Beam Formation (ZFBF). The aforementioned RBF or ZFBF methods may perform similarly to the optimal performance achieved by the DPC method if the number of users increases in the multiuser environment.

In the meantime, a code key for use in the MIMO communication system will be described below.

A general communication system performs coding of transmitter transmission information using an early error correction code and transmits the coded information so that an error occurring on a channel can be corrected by a receiver. The receiver demodulates a received signal (Rx) and decodes the early error correction code on the demodulated signal so that it recovers the transmission information. By the decoding process, the Rx signal error caused by the channel is corrected.

Each of the early error correction codes has a maximum correctable limitation on a channel error correction. In other words, if a receive signal (RX) has an error that exceeds the limitation of a corresponding early error correction code, a receiver cannot decode the Rx signal into error-free information. Therefore, the receiver must determine the presence or absence of an error in the decoded information. Accordingly, a specialized coding process is required to perform error detection separately from the early error correction coding process. In general, a Cyclic Redundancy Check (CRC) code was used as an error detection code.

The CRC method is an exemplary coding method for performing error detection. In general, the transmission information is encoded by the CRC method and then the early error correction code is applied to the CRC encoded information. In general, a single unit coded by the CRC and the early error correction code is called a code key.

In the meantime, if several transmission information units are overlapped and then received, the present invention can expect performance improvement using an interference-canceling receiver. There are many cases in the above case in which various transmission information is overlaid and then received, for example, a case in which MIMO technology is used, a case in which a multiuser detection technology is used, and a in which case a multicode technology is used. A brief description of the interference cancellation structure will be as follows.

According to the interference cancellation structure, after the first information is demodulated / decoded from a total receive signal in which various information is overlaid, information associated with the first information is removed from the total receive signal. A second signal is demodulated / decoded by the resulting signal without first information removed from the receiving signal. A third signal is demodulated / decoded by the resulting signal without first and second information removed from the first receive signal. A fourth signal, or other signal after the fourth signal, repeats the above processes so that the fourth or other signal is demodulated / decoded. Thus, the aforementioned method for continuously removing the demodulated / decoded signal from a receive signal to improve performance of the next demodulation / decoding process is called a Successive Interference Cancellation (SIC) method.

In order to use the abovementioned interference cancellation method, such as SIC1 the demodulated / decoded signal removed from the receive signal must have no error. If an error occurs in the demodulated / decoded signal, an error propagation occurs so that a negative influence continuously affects all demodulated / decoded signals.

The abovementioned interference cancellation technology may also be applied to MIMO technology. If several pieces of transmission information are overlaid / transmitted via multiple antennas, the above interference cancellation technology is required. In other words, if spatial multiplexing technology is used, each transmitted information is detected and, at the same time, interference cancellation technology can be used.

However, as described above, in order to minimize the error propagation caused by interference cancellation, it is preferable that the interference be selectively removed after determining the presence or absence of an error in the decoded / decoded signal. . A representative method for determining the presence or absence of error in each transmission information is the above-mentioned cyclic redundancy check (CRC) method. A distinctive information unit processed by CRC coding is called a code key. Therefore, a more representative method for using interference cancellation technology is a specific case in which various parts of the transmission information and various code keys are used.

In the meantime, the number of rows and number of columns of an H channel array indicating a channel condition are determined by the number of Tx / Rx antennas. In the channel matrix Η, the number of rows is equal to the number (Nr) of Rx antennas, and the number of columns is equal to the number (Nt) of Tx antennas. Namely, the H channel matrix is denoted by Nr x Nt arrays.

In general, a matrix classification is defined by a smaller number between the number of rows and the number of columns, in which the rows and columns are independent of each other. Therefore, the array rating cannot be higher than the number of rows or columns. The H channel matrix rating can be represented by the following Equation 13:

Equation 13

rating (H) <min (NT, Nr)

Another definition of the aforementioned classification can be defined by the number of peculiar values other than "0" when the matrix is decomposed by special value. Similarly, if the classification is processed by SVD, the classification can also be defined by the number of singular values other than "0". Therefore, the physical significance of classification in the channel matrix can be considered a maximum number of times of transmission of a given channel that can transmit different information.

For convenience of description, each of the different pieces of information transmitted via MIMO technology is considered to be a continuous stream or a continuous stream of data. This continuous data stream can also be called a layer, so that the number of transmission streams cannot be greater than the channel rating equal to the maximum number of times the channel can transmit different information. .

If the channel matrix is H, then this channel H matrix can be represented by the following Equation 14: Equation 14

# Of data streams ^ classification (H) <min (NT, Nr) where "number of streams of data" is indicative of the number of streams of data.

In the meantime, it is clear that a single continuous stream of data can be transmitted via one or more antennas.

A method for matching the continuous stream of data to the antenna can be described according to MIMO technology types.

In the case where a single continuous stream of data is transmitted via multiple antennas, this case can be considered as the spatial diversity scheme. In the case where several continuous streams of data are transmitted through several antennas, this case may be considered the spatial multiplexing scheme. Needless to say, a hybrid scheme between the spatial diversity scheme and the spatial multiplexing scheme can also be made available. The relationship between the code key and the streaming of data in the MIMO communication system will be described in more detail below.

Figure 4 is a block diagram illustrating the relationship between the code key and the continuous flow of data in the MIMO communication system.

A variety of methods for matching the code key with streaming data are made available. One general method, among several methods, generates code key (s), allows each code key to enter a code key mapping module - streaming data, home to the code key received from the code module. key code mapping - streaming data with the data stream (s), and transmit the data stream to the data stream - antenna mapping module so that the stream data stream is transmitted via the Tx antenna.

A part for determining the combination of the code key and the continuous data stream is denoted by a bold bold line in Figure 4.

Ideally, the relationship between the code key and the continuous flow of data can be freely determined. A single code key can be divided into multiple streams of data so that streams of split data are transmitted to a destination. Several code keys are serially integrated into a data stream so that this data stream that includes the code keys can be transmitted to a destination.

However, the aforementioned serial integration of the various code keys may be considered a type of predetermined coding process, so that the present invention considers that a single code key is matched to one or more continuous streams of data from a combination. with real meaning. However, as long as several continuous streams of data are distinguished from each other without departing from the scope or spirit of the present invention, the present invention may also be applied to the distinguished continuous streams of data.

Therefore, for convenience of description, the present invention considers that a single code key is matched to one or more continuous streams of data. Therefore, if all information is encoded and then transmitted to a destination, the following Equation 15 can be acquired:

Equation 15

# of code keys <number of data streams where "number of code keys" is the number of code keys, and "number of data streams" is the number of data streams .

In conclusion, the above mentioned Equations 13 to 15 can be represented by the following Equation 16:

Equation 16 # of code keys <number of streams of data <rating (H) <min (NT, Nr)

By Equation 16, the following fact can be recognized. In other words, if the number of Tx / Rx antennas is limited, a maximum number of continuous data streams is also limited. If the number of code keys is limited, a minimum number of continuous data streams is also limited.

By the above relationship between the code key and data stream, if the number of antennas is limited, the maximum number of code keys or data streams is limited, so that the limited number of code keys is limited. can be combined with the limited number of continuous data streams.

The aforementioned combination of the code key and the continuous data flow is required for both an uplink and a downlink.

For example, MIMO technology is considered to be applied to the downlink. In this case, a receiver must be correctly informed in advance of a combination that is used for the aforementioned transmission of information between all combinations of the code key and the data stream, so that the demodulation / decoding process information is correctly performed.

Also, if the control information is transmitted to the uplink, a preferred combination of various combinations of the code key and the data stream should also be recognized by a receiver. In more detail, in order to implement MIMO technology, a transmitter must recognize the channel and status information of a receiver, so that the receiver must notify various control information via the uplink.

For example, the receiver considers a variety of receiver states (for example, a measured channel or temporary storage state), and should notify a preferred combination of a code key and a continuous data stream, an indicator. channel quality (CQI) corresponding to this preferred combination, and a corresponding precoding matrix index (PMI) thereof. Needless to say, the contents of the detailed control information may be differently determined according to the type of MIMO technology used. However, the aforementioned fact in which the receiver must inform the uplink about the preferred combination of code key and streaming data is unchanging.

As another example, if MIMO technology is applied to the reverse link, only one transmission link changes to another link, unlike the above description of the example, and the remaining facts other than the transmission link change are the same. those of the above example, so that any combination between a code key and a continuous stream of data, a combination used and a preferred combination must be notified.

If all combinations of the code key and the continuous stream of data can be indicated by a small number of bits, the control information can be more effectively transmitted to a destination. Therefore, a method is required to effectively indicate the combination of the code key and the continuous flow of data.

disclosure

Technical problem

Accordingly, the present invention is directed to a layer mapping method and a data transmission method for a MIMO system that substantially avoids one or more problems due to the limitations and disadvantages of related technology.

An object of the present invention is to provide a method for rationally limiting the number of combinations between a code key and a continuous stream of data and for reducing the number of information bits indicating the number of combinations.

Another object of the present invention is to provide a method for limiting the number of combinations of a code key and a data stream in a multiuser MIMO communication system to reduce the number of information bits required. to indicate the number of combinations, and to provide an effective communication service.

Still another object of the present invention is to provide a data processing method for effectively splitting a single code key into at least two layers when data is transmitted via multiple Tx antennas in a wireless communication system.

Still another object of the present invention is to provide a data processing method for transmitting data via multiple Tx antennas to reduce an influence of the fading phenomenon on a wireless communication system.

Additional advantages, objects and features of the invention will be set forth in part in the following description and in part will be apparent to those skilled in the art by examining the following, or may be learned from the practice of the invention. The objects and other advantages of the invention may be realized and achieved by the structure particularly pointed out in the written description and its claims, as well as in the accompanying drawings.

Technical Solution

In order to achieve these objectives and other advantages, and in accordance with the purpose of the invention, as incorporated herein and widely described, a layer mapping method for spatial multiplexing in a Multigrade and Multisite system (MIMO) comprises: a) modulating a predetermined bit block each of at least one code key, and generate a continuous stream of modulation data for each code key; and (b) map a modulation symbol for each of the at least one code key to at least one layer according to a specific combination of predetermined mapping combinations, wherein in each of the mapping combinations. predetermined, the number of layers to which a single code key is mapped is limited to a predetermined number or less when the predetermined number corresponds to an acquired ratio when the number of all layers is divided by number of all code keys.

Preferably, the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination limits the number of layers to which the single code key is mapped to 2 or less.

Preferably, in the predetermined mapping combination, a combination in which a single code key is mapped to at least two layers when a maximum of one code key is used is removed between all available mapping combinations between at least one code key and at least one layer.

Preferably, in the predetermined mapping combination, a combination in which a single code key is mapped to at least two layers when a maximum number of all layers is 2 is removed between all available mapping combinations between at least one code key and at least one layer.

Preferably, the predetermined mapping combination is limited in one combination, where one lower index code key is mapped to a single layer and the other higher index code key is mapped to two layers. , when the two code keys map to up to three layers.

Preferably, the predetermined mapping combination is a combination in which combinations, each of which have the same number of code keys and layers, are denoted by a single combination.

Preferably, the MIMO system uses a maximum of 4 layers and a maximum of 2 30 code keys, and the predetermined mapping combination consists of a first combination in which a single code key is mapped to a single layer, a second combination in which two code keys are mapped to two layers respectively, a third combination in which two code keys are mapped to three layers, and a fourth combination in which two code keys are mapped. Up to four layers.

Preferably, the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination consists of a first combination in which a single code key is mapped to a single layer, a second combination in which two code keys are mapped to two layers respectively, a third combination in which two code keys are mapped to three layers, a fourth combination in which two code keys are mapped to four layers layers, and a fifth combination to support relaying based on a Hybrid ARQ (HARQ) scheme.

Preferably, in the third combination, a first code key between the two code keys is mapped to a first layer between the three layers, and a second code key between the two code keys is mapped to the second and third layers between the three layers.

Preferably, in the fourth combination, a first code key between the two code keys is mapped to the first and second layers between the four layers and a second code key between the two code keys is mapped. up to the third and fourth layers between the four layers.

Preferably, in layer mapping step b), if a specific code key is mapped to two layers according to the third or fourth combinations between predetermined mapping combinations, the continuous streams of modulation symbols. that build a specific code key are alternatively mapped to both layers.

In another aspect of the present invention, there is provided a method for allowing a transmitter of a Multitrack and Multisided (MIMO) system to transmit data via multiple transmit antennas (Tx) which comprise: a) performing a channel coding in a specific data block; b) modulating a bit block formed by the coded data block with respect to the channel and generating a continuous stream of modulation symbols; c) mapping modulation symbols contained in the continuous flow of modulation symbols to at least one layer according to any of the predetermined mapping combinations; and d) transmitting the mapped layer symbols, wherein each of the predetermined mapping combinations includes a specific combination in which a single code key consisting of the continuous stream of symbols generated by modulation of the specific data block is mapped to at least two layers, and the specific combination is designed to alternatively map the continuous flow of symbols that builds the single code key to at least two layers.

Preferably, the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination includes a first combination in which a single code key is mapped to a single layer, a second combination in the which two code keys are mapped to two layers, respectively, a third combination in which two code keys are mapped to three layers, and a fourth combination in which two code keys are mapped to four layers.

Preferably, in the third combination, a first code key between the two code keys is mapped to a first layer between the three layers, and a second code key between the two code keys is mapped to the second and third layers. between the three layers.

Preferably, in the fourth combination, a first code key between the two code keys is mapped to the first and second layers between the four layers, and a second code key between the two code keys is mapped to the third and fourth layers between the four layers.

Preferably, in layer mapping step c), if a specific code key is mapped to two layers according to the third or fourth combinations between the predetermined mapping combinations, an index symbol in even ordinal position between continuous streams of symbols constructing a specific code key are mapped to a first layer between the two layers, and an odd ordinal index symbol is mapped to a second layer between the two layers, so the symbol of index in even ordinal position and index symbol in odd ordinal position are alternatively mapped to the first and second layers.

Both the foregoing general description and the following detailed description of the present invention are understood to be exemplary and explanatory, and are not intended to provide further explanation of the invention as claimed.

Advantageous Effects

The method for indicating a combination of a code key and a continuous data stream according to one embodiment of the present invention may rationally limit the number of all combinations between a code key and a continuous data stream. consideration for a variety of aspects, so that it can reduce the number of bits of information indicating the number of all combinations of a code key and a continuous stream of data. As for the above aspects, the above method considers a maximum baud rate of a specific code key, compares usability with the number of cases indicating a matching combination, keeps a combination available for retransmission, improves performance receiver decoding using the Successive Noise Canceling (SIC) method, considers a streaming stream grouping based on an antenna array, and considers a user convenience in a multiuser MIMO communication system.

Therefore, the present invention indicates all key code - streaming data combinations that are required for both an uplink and a downlink in a lower bit number MIMO communication system, thereby increasing efficiency. of control information.

The present invention provides a method for mapping layered code blocks in a MIMO communication system, transmitting the mapped code blocks, and additionally ensuring a gain in spatial diversity caused by spatial multiplexation.

In the event that a single data block is divided into several code blocks and the code blocks are coded by channel, the present invention gives each code block sufficient spatial diversity by adding simple functions to a transmission chain.

Brief Description of the Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and, together with the description, serve to explain the principle of the invention.

In the drawings:

Figure 1 is a block diagram illustrating a conventional MIMO communication system;

Figure 2 shows channels from Nt Tx antennas to an Rx antenna (i); Figure 3A is a conceptual diagram illustrating a single user MIMO communication system;

Figure 3B is a conceptual diagram illustrating a multiuser MIMO communication system;

Figure 4 is a block diagram illustrating the relationship between a code key and a continuous stream of data in a MIMO communication system;

Fig. 5A is a block diagram illustrating a MIMO communication system in which a maximum number of code keys is 2 and a maximum number of antennas is 4 according to the present invention;

Fig. 5B is a block diagram illustrating a MIMO communication system in which a maximum number of code keys is 2 and a maximum number of antennas is 2 according to the present invention;

Fig. 6 is a conceptual diagram illustrating a modulation coding set (MCS) provided when a single code key is transmitted via multiple data streams in accordance with the present invention;

Fig. 7 is a conceptual diagram illustrating a concept of interference interference cancellation (SIC) realized at a receiver to improve the decryption performance of a code key in accordance with the present invention;

Figure 8A shows a specific case in which a single code key is transmitted through two continuous streams of data and determines whether the SIC is performed in this case;

Figure 8B shows a specific case in which two code keys are transmitted via two continuous streams of data respectively and determines whether the SIC is performed in this case;

Figure 9 shows that two code keys are transmitted via two continuous streams of data, one code key is successfully received and the other code key is no longer received, and a retransmission of the code key is not received. is requested;

Figures 10A-10C show a variety of methods for grouping multiple antennas in various ways;

Figure 11 shows the number of streams of data available from a user in a multiuser MIMO communication system;

Figure 12 shows a simulation result indicating a difference in system throughput between a first case where only one code key is used and a second case where two code keys are used on the condition that there are several continuous streams of data;

Figures 13A - 13C show the simulation results of performance at the receiving station according to the order of SIC decoding;

Figure 14 shows the simulation result of receiving station performance when the number of all combinations between a code key and a continuous data stream is limited to a specific number of combinations that can be indicated. by a given number of bits;

Fig. 15 is a block diagram illustrating a wireless communication system;

Fig. 16 is a block diagram illustrating a transmitter according to one embodiment of the present invention;

Fig. 17 is a block diagram illustrating a transmission according to another embodiment of the present invention;

Fig. 18 is a block diagram illustrating a channel coding scheme according to one embodiment of the present invention;

Fig. 19 is a conceptual diagram illustrating data transmission according to one embodiment of the present invention;

Figure 20 is a conceptual diagram illustrating a data transmission according to another embodiment of the present invention;

Fig. 21 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention; Fig. 22 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention;

Fig. 23 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention;

Fig. 24A is a block diagram illustrating a data processing method of a transmitter according to an OFDMA scheme;

Fig. 24B is a block diagram illustrating a receiver data processing method according to an OFDMA scheme;

Fig. 25 is a conceptual diagram illustrating a method for separating a systematic part and a parity part of a coded code block from each other, and for performing a velocity matching of the separated parts;

26A-26B are conceptual diagrams illustrating a single code key (SCW) and multiple code keys (MCW), respectively;

Fig. 27 shows a coding string used for an HS-DSCH of a WCDMA system according to the present invention;

Figure 28 shows a downlink FDD subframe structure of an LTE system according to the present invention;

Figures 29A - 29B show transmission chain structures of an LTE system according to the present invention;

Figure 30 shows a transmission chain structure according to one embodiment of the present invention;

31A - 31B show transmission chain structures according to another embodiment of the present invention;

32A - 32B show transmission chain structures according to yet another embodiment of the present invention; and

Fig. 33 shows a transmission chain structure according to another embodiment of the present invention.

Best Mode

Now, reference will be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or equal parts.

Prior to describing the present invention, it is understood that most of the terms disclosed in the present invention correspond to the general terms well known in the art, but some terms have been selected by the applicant as needed and will henceforth be disclosed in the following description of the present invention. . Therefore, it is preferable that the terms defined by the applicant are understood based on their meanings in the present invention.

For convenience of description and better understanding of the present invention, general structures and devices well known in the art will be omitted or denoted by a block diagram or flow chart. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or equal parts.

The present invention provides a method for rationally limiting the number of all combinations of a code key and a continuous stream of data, and for reducing a number of bits of information indicating the limited number of combinations. To this end, the present invention considers the method for rationally limiting the number of all combinations after considering the number of combinations available between a code key and a continuous data stream.

If the number of Tx / Rx antennas is limited, as shown in Equation 16, a maximum number of continuous data streams is limited. E1 then, if the number of code keys is limited, a minimum number of continuous data streams is also limited.

Examples associated with the above case will be described below.

If the number of Tx / Rx antennas is 4, a maximum number of data streams or code keys is 4. In the meantime, if the number of code keys is limited, a minimum number of available data streams is available. It is limited. If the number of code keys is 2, the number of streams of data is equal to or greater than "2" or more. Therefore, if a minimum value of Tx / Rx antennas is 4 and the number of code keys is 2, the number of available data streams can be 2, 3, or 4. If a minimum value of Tx / Rx antennas for 2 and the number of code keys for 2, the number of streams of data available is only "2".

In general, the number of Tx / Rx antennas is 4 or 2 in commercial cases, and a maximum number of code keys is 2. In recent times, according to 3GPP LTE, a maximum number (Nt) of Tx antennas / was set to 4, a maximum number (Nr) of Rx antennas was set to 4, and a maximum number of allowable multicode keys was set to 2, which was prescribed in 3GPP, R1-063013 (Approved minutes of 3GPP TSG RAN WG1 # 46 in Tallinn (Tallinn, Estonia, August 28 - September 1, 2006)), and 3GPP, R1-063613 (Approved Report of 3GPP TSG RAN WG1 # 46bis (Seoul, Korea, 09 - 13 of October 2006).

Therefore, the following description of the present invention assumes that the number of Tx / Rx antennas is 4 or 2 and that the maximum number of code keys is 2, but the scope of the present invention is not limited to this consideration, and may also be applied to other combinations if necessary. A method of combining a code key and a continuous data stream provided that the number of Tx / Rx antennas is 4 or 2 and the maximum number of code keys is 2 will be described below.

Figure 5A is a block diagram illustrating a MIMO communication system in which a maximum number of code keys is 2 and a maximum number of antennas is 4 according to the present invention. Figure 5B is a block diagram illustrating a MIMO communication system in which a maximum number of code keys is 2 and a maximum number of antennas is 2 according to the present invention.

Referring to Figure 5A, if the number of antennas is "4", a maximum number of continuous data streams is limited to "4". Therefore, if the number of code keys is "1", the number of available data streams is 1, 2, 3, or 4. If the number of code keys is "2", the number of streams available data is 2, 3 or 4.

Referring to Figure 5B, if the number of antennas is "2", a maximum number of continuous data streams is limited to "2". Therefore, if the number of code keys is "1", the number of available data streams is 1 or 2. If the number of code keys is "2", the number of available data streams is set to only "2"

In this case, the present invention pays attention to the combination of the code key and the continuous data stream, rather than the combination of the continuous data stream and the antenna. This combination of the code key and the data stream is denoted by a bold bold line in Figures 5A and 5B.

In fact, the combination of streaming data and antenna is differently decided according to the categories of a MIMO system. In this way, a data stream number is fixed under a given constraint condition, and only the combination of the code key and the data stream under the same constraint condition will be considered.

If the maximum number of continuous data streams is 4 and the maximum number of code keys is 2, as shown in Figure 5A, the following combination is made, and a detailed description of this is given below.

If the number of antennas is 4, that is, if the maximum number of data streams is 4, and the maximum number of code keys is 2, all combinations between a code key and a data stream are as follows. shown in the following tables 1 and 2;

Table 1

<table> table see original document page 24 </column> </row> <table> <table> table see original document page 25 </column> </row> <table>

Table 2

<table> table see original document page 25 </column> </row> <table> <table> table see original document page 26 </column> </row> <table> <table> table see original document page 27 < / column> </row> <table> 25

In this case, Table 1 shows examples of individual combinations when the number of code keys is 1, and Table 2 shows examples of individual combinations when the number of code keys is 2.

The order of the code keys in the aforementioned Tables 1 or 2 is not important. In general, each code key includes specific information (for example, a packet number) that can discriminate each code key. Therefore, the present invention considers how many code keys were transmitted rather than considering the order of code keys. If each data stream is mapped to an antenna, the antenna mapping operation changes according to the order of the data streams. Also, if a pre-coding is used, the mapping operation also changes according to the pre-coding order taking into account a corresponding weighting vector. Therefore, the continuous flow of data has a fixed order, so that it must indicate the order of the combinations.

As you can see from Tables 1 and 2, if the number of code keys is 1, the number of combinations is 15. If the number of code keys is 2, the number of combinations is 25. So the A total of 40 combinations is required. Therefore, in the event that all combinations are allowed without any restrictions on condition that the maximum number of code keys is 2 and the maximum number of continuous data streams is 4, the combinations must be denoted by 6 bits (25 = 32 <40 <26 = 64).

In the meantime, as shown in Figure 5B, if the maximum number of continuous data streams is 2, and the maximum number of code keys is 2, all combinations of the code key and the data stream are as follows.

As shown in Figure 5B, if the number of antennas is 2, that is, if the maximum number of continuous data streams is 2, and if the maximum number of code keys is 2, all cases of individual combinations are of the shown in the following Table 3:

Table 3 <table> table see original document page 28 </column> </row> <table>

The above Table 3 shows exemplary combinations provided when the number of code keys is 1 or 2.

If the maximum number of data streams is 2 and the maximum number of code keys is 2, as shown in Table 3, a total of 4 code key combinations - data stream is required. . In this case, if all combinations are allowed without any restrictions, the 4 key code - streaming data combinations must be denoted by 2 bits (21 = 32 <4 <22 = 4). However, this case can be considered a subset of the specific case using a maximum of 4 continuous data streams shown in Tables 1 or 2. Therefore, as long as the present invention can effectively indicate the above case employing a maximum of 4 continuous data streams, it can also be applied to another case employing a maximum of two continuous data streams.

In the meantime, where the combination of a code key and a data stream is independently indicated according to the number of antennas, this case is left out of consideration because the number of bits used is a small number. . Therefore, the following embodiments of the present invention will disclose a method for effectively indicating all combinations of a code key and a smaller bitstream data stream based on a specific case in which a maximum of 4 data streams is used. If the combination of the code key and the stream of data can be denoted with fewer bits, a control signal transmission efficiency can be improved.

If a given limitation between a code key and a data stream is one where the maximum number of data streams is 4 and the maximum number of code keys is 2, all combinations of the code key and the Streaming data is made available so that a total of 6 bits is required to indicate all combinations without any restrictions. One embodiment of the present invention provides a method for limiting all combinations of the code key and continuous data flow to reduce the number of units of information indicating a combination used between combinations.

In order to implement the aforementioned embodiment, a method for limiting the number of Tx data streams through which each code key is transmitted and reducing the number of all combinations of the code key and the stream. data will be described below.

Figure 6 is a conceptual diagram illustrating a modulation coding set (MCS) provided when a single code key is transmitted via several continuous streams of data in accordance with the present invention.

Referring to Figure 6, if several continuous streams of data are transmitted via multiple antennas, each continuous stream of data passes through a variety of channel environments. In this case, if a single code key (for example, a code key 1) is transmitted through several continuous data streams (eg continuous data streams 1 - 3), different channel streams environments Individual data streams are immediately weighted during decoding of a corresponding code key.

As shown in Figure 6, if code key 1 is transmitted via a first data stream 1 based on a 256QAM and an MCS of an encoding speed = 8/9, a second data stream 2 based on a 64QAM and an MCS of a coding speed of 1/2, and a third continuous data stream 3 based on a BPSK and an MCS of a coding speed = 1/10, a Code key 1 has the same effect as when code key 1 is transmitted with an average MCS level of the MCS levels of the first to third continuous data streams, so that efficiency may be lower than that. in another case in which a code key requiring high speed transmission is transmitted over a good continuous stream of data.

In light of the channel capacity, it is more preferable that each code key be appropriately transmitted according to the channel environments of the individual data streams, so that it is also preferable for a single code key to be transmitted each continuous flow of data. In other words, as long as there are four code keys if four continuous streams of data are used to transmit the four code keys, the optimal condition can be provided.

However, according to the above case in which a maximum of 4 continuous data streams is used and a maximum of 2 code streams is used, if a maximum of 4 continuous streams of data is to be used under a given condition, each key The code code shall be transmitted through at least two continuous streams of data.

Therefore, one embodiment of the present invention limits the number of continuous Tx data streams through which each code key is transmitted so that a given code key is transmitted via a minimum number of continuous streams. between all continuous streams of data. As a result, the number of all combinations of a code key and a continuous stream of data is reduced.

In more detail, according to this embodiment in which a maximum of 4 continuous data streams is used and a maximum of 2 code streams is used, it is preferable to limit the key code streams - data streams in such a way. that a single code key should be limited to up to two continuous streams of data.

Then, the combination of the code key and the data stream can be represented by the following Tables 4 and 5:

Table 4

<table> table see original document page 30 </column> </row> <table> <table> table see original document page 31 </column> </row> <table> <table> table see original document page 32 < / column> </row> <table> The above Table 4 shows an exemplary combination between a code key and a data stream when the number of code keys is 1. The above Table 5 shows an exemplary combination between a code key and a continuous stream of data when the number of code keys is 2.

As can be seen from Tables 4 and 5, as long as a single code key is transmitted over a maximum of 2 continuous data streams according to one embodiment of the present invention, the number of combinations is 10. when a maximum number of code keys is 1, and the number of combinations is 21 when a maximum number of code keys is 2, so a total of 31 combinations is required. The 31 combinations can be denoted by 5 bits (24 = 16 <31 <25 = 32).

In the meantime, a more preferred embodiment of the present invention limits the number of streams of data used to transmit a single code key and at the same time removes a specific combination with many more case numbers than is possible to use. , so that the number of all combinations can be further reduced, and a detailed description of this will be given below.

In more detail, one embodiment of the present invention further considers a specific condition that excludes a specific case in which three continuous streams of data are adapted to transmit the code key of all combinations shown in Tables 4 and 5.

Although the above case in which three continuous streams of data are used corresponds to a channel rating of 3, the channel rating of 3 may change to another rating so that the changed rating may be indicated. The reason why the above case in which three continuous streams of data are used among several continuous streams of data is excluded is that the number of combinations made in the case of three continuous streams of data is 12, as shown in Table 5, so that 12 combinations occupy about 38.7% of all combinations, but the possibility of selecting the case in which three continuous streams of data are used is about 20%, according to the result. of simulation.

Therefore, it is preferable that the case with many more combinations than the possibility of being selected for transmission be excluded from all cases. As a result, the aforementioned embodiment of the present invention removes the combination with many case numbers of all combinations of a code key and a continuous data stream, so that the number of control information bits is effectively reduced. .

A detailed example associated with the above description can be represented by the following Table 6:

Table 6 <table> table see original document page 34 </column> </row> <table> <table> table see original document page 35 </column> </row> <table>

According to the embodiment of the present invention shown in Table 6, as long as a specific combination with many more case numbers (i.e. the case in which three continuous streams of data are used) than the possibility of use is removed, the number of combinations between a code key and a data stream is 10 when a maximum number of code keys is 1, and the number of combinations between a code key and a data stream is 9 when a maximum number of code keys is 2, so a total of 19 combinations are required.

Therefore, one embodiment in which a single code key is transmitted over a maximum of 2 continuous data streams and the case employing three continuous data streams is excluded can be denoted by 5 bits (24 = 16 <19 <25 = 32). In this case, the number of bits of the control information that indicates all combinations may be less than that of Tables 4 or 5, however, if the above is applied to another example, all combinations may be denoted with fewer numbers. bit

In the meantime, another embodiment of the present invention limits the number of continuous data streams used to transmit a single code key and at the same time removes a specific combination with many more case numbers than can be used. . And, if two continuous streams of data are used to improve reception performance, the aforementioned embodiment of the present invention removes a combination in which a single code key is transmitted via two continuous streams of data. that it can further reduce the number of all combinations between a code key and a continuous stream of data. A detailed description of the above mentioned embodiment will be given below.

Fig. 7 is a conceptual diagram illustrating a concept of successive interference cancellation (SIC) realized at a receiver to improve the decryption performance of a code key in accordance with the present invention.

If multiple code keys are received at one receiver, the receiver can perform the SIC to improve decoding performance of an Rx signal. If the receiver simultaneously receives a code key 1 and a code key 2, as shown in Figure 7, it first decodes the code key 1, removes all signals associated with the decoded code key 1 from all. Rx signals and decode code key 2 using the remaining signals, so that the decoding performance of all signals can be improved.

In this case, in order to realize the above-mentioned SIC, there is a need for several code keys to be transmitted as shown in figure 7. If a single code key is distributed to several continuous streams of data, then it is transmitted. - da, although several streams of data are received, the receiver cannot perform the SIC shown in figure 7.

Figure 8A shows a specific case in which a single code key is transmitted via two continuous streams of data, and it is determined whether the SIC is performed in this case. Figure 8B shows a specific case in which two code keys are transmitted by two continuous streams of data respectively and it is determined whether the SIC is performed in this case.

Referring to Figure 8A, if a single code key is transmitted via two data streams, an independent code key is not contained in each of the two Rx data streams, so that the SIC cannot be applied to the case of figure 8A.

Referring to Figure 8B, if two code keys are transmitted via two continuous data streams, the SIC shown in Figure 7 may be applied to an Rx signal transmitted through each continuous data stream, so that the performance Rx signal decoding can be improved.

Therefore, another embodiment of the present invention limits the number of data streams used to transmit a single code key as shown in Table 6 (e.g. 2 data streams or below 2) and removes a com- specific combination with many more case numbers than is possible to use (for example, the combination in which three continuous streams of data are allowed to be removed). And, if two streams of data are used to further limit the number of bits that indicate all key code streams - data streams, the aforementioned embodiment of the present invention removes a combination (shown in Figure 8A) in which A single code key is transmitted over two continuous streams of data so that a receiver can improve decoding performance of an Rx signal using the SIC.

In this case, the above example has no combination in which the number of continuous data streams is 3. If the number of continuous data streams is 1, 2, or 4, there is only one key code - continuous data stream combination. shown in the following Table 7:

Table 7

<table> table see original document page 36 </column> </row> <table> <table> table see original document page 37 </column> </row> <table>

Referring to Table 7, the number of combinations is 4 when a maximum number of code keys is 1, and the number of combinations is 9 when a maximum number of code keys is 2, so a total of 13 combinations is required. Therefore, in the case of this example according to this embodiment, all combinations between a code key and a continuous data stream can be denoted by 4 bits (23 = 8 <13 <24 = 16). Therefore, in light of the number of bits that indicates all combinations, the Table 7 method is better than the Table 6 method.

In the interim, the aforementioned embodiments of the present invention have considered channel capacity, combination indication efficiency, and SIC-based performance improvement Rx in order to effectively reduce the number of all combinations between a code key. and a continuous flow of data.

If you only consider the efficiency in reducing the number of all key code - streaming data combinations, if a receiver of a HARQ communication system generates a relay request, an unexpected problem may occur in the proper handling of the data request. relay.

Therefore, another embodiment of the present invention limits the number of all code key combinations - streaming data by removing a specific combination with many more case numbers than the possibility of using all combinations and maintains a combination available for a relay scheme such as a HARQ. A detailed description of the above mentioned embodiment will be given below.

Figure 9 shows that two code keys are transmitted via two continuous streams of data, one code key is successfully received and the other code key is no longer received, and a retransmission of the code key not received. is requested.

Referring to Figure 9, if two code keys are transmitted by two continuous streams of data during a first transmission, it is considered that a code key 1 between the two code keys is successfully received and that a code key is received. code 2 corresponding to the other code key is no longer received so that a NACK signal is transmitted to a transmitter. In this case, if the "Chase Combination" scheme is applied to relay, it is preferable that code key 2 be relayed via two continuous streams of data.

However, the aforementioned combination is not contained in the combinations shown in Table 7. Therefore, one embodiment of the present invention removes a specific combination with many more case numbers than the possibility of use between all combinations (for example, one combination). with three continuous streams of data) and keeps the aforementioned combination available for the relay scheme such as HARQ. The aforementioned embodiment of the present invention may be represented by the following Tables 8 and 9:

Table 8

<table> table see original document page 38 </column> </row> <table> <table> table see original document page 39 </column> </row> <table>

Table 9

<table> table see original document page 39 </column> </row> <table> <table> table see original document page 40 </column> </row> <table>

The above Table 8 shows a combination of a code key and a continuous flow of data when a single code key is used. The above Table 9 shows a combination of a code key and a continuous flow of data when two code keys are used.

As can be seen from Tables 8 and 9, a specific combination with many more case numbers than the possibility of use (ie a specific case with three continuous streams of data) is excluded from all combinations of the case. above example in which a maximum of 4 continuous streams of data is used and a maximum of 2 keys of code is used. If a specific combination in which a single code key that can be used for relaying is transmitted through two or four continuous streams of data, and a combination in which each of the two code keys is transmitted by means of one or two streams of data are maintained, 11 combinations are made available for the case where a single code key is used, and 9 combinations are made available for the other case where two code keys are used, so that a total of 20 combinations are made available. Therefore, all combinations can be denoted by bits (24 = 16 <20 <25 = 32).

5 bits are required as a number of bits to indicate the combination of a code key and a continuous stream of data shown in Tables 8 and 9, so that the number of combinations for use in a particular case can be further limited. resulting in a reduction in the number of matching combinations. The following table 10 shows that a combination in which two code keys are transmitted via two continuous streams of data is further limited.

Table 10

<table> table see original document page 40 </column> </row> <table> <table> table see original document page 41 </column> </row> <table>

Referring to Table 10, the number of combinations is 11 when a maximum number of code keys is 1, and the number of combinations is 3 when a maximum number of code keys is 2, so a total of 14 combinations are required. Therefore, the aforementioned case, in which the case of three streams of data is excluded, the combination in which retransmission is considered held and two code keys are transmitted via two streams of data, can be denoted by the information. 4-bit control (23 = 8 <13 <24 = 16).

In the meantime, according to the detailed embodiments of the present invention which relate to Tables 3-10, the number of bits (i.e. a bit number) of the control information required to indicate all combinations of a code key and A continuous stream of data is determined as a number of bits that can indicate the energy of 2 greater than the number of all combinations. In this case, the number of key code - data stream combinations that can be denoted by a number of bits of the required control information is generally larger than the number of all combinations for which a predetermined constraint is applied.

Therefore, with respect to Tables 3-10, another embodiment of the present invention adds additional combinations corresponding to a difference (e.g. 3 combinations in Table 10) between the number of combinations (e.g. 16 combinations in Table 10) , denoted by the number of pieces of information (for example, 4 bits in Table 10) indicating all limited combinations, and the number of all Unlimited combinations (for example, 13 combinations in Table 10) for all limited combinations, and a detailed description of this will be given below.

The cases shown in Tables 6-10 indicate the cases in which the combination is excluded for the case that the number of cases is greater than the possibility of use, such as the case where the number of continuous data streams is " 3 ", so that the number of bits required to indicate all combinations can be greatly reduced. However, the aforementioned cases shown in Tables 6-10 cannot indicate the case in which three continuous streams of data are used, while they may reduce the number of combinations, resulting in an unexpected problem occurring.

In the meantime, there is a difference between the maximum number of combinations denoted by the number of bits required to indicate all combinations and the number of combinations actually used. In other words, the number of actual combinations is assumed to be M, and N bits are required to indicate the combinations according to an equation of 2N1 <M <2n. As a result, a predetermined number of combinations corresponding to a difference (2N - M) between the number (2N) of the maximum expressible combinations denoted by N bits and the number (M) of combinations can be added further. real actions.

Therefore, one embodiment of the present invention adds specific combinations in which three continuous streams of data are used. The number of specific combinations corresponds to a difference between the number of combinations, denoted by a number of bits required to indicate all combinations, and the number of all actual combinations. Thus, this embodiment provides a method for using three continuous streams of data without increasing the number of bits required to indicate all combinations.

In more detail, Table 7 can indicate all combinations (ie 13 combinations) limited by 4-bit control information. In this case, a specific combination employing three continuous streams of data corresponding to a difference between 16 combinations that can be denoted by the control information and 13 combinations can be added to the combinations in Table 7. In this way , the case of Table 10 may additionally include two combinations, each using three continuous streams of data.

However, the number of combinations occupied by the case employing three continuous streams of data is greater than the number of combinations that can be added. In other words, the number of cases, each of which using a single code key, among several cases, each of which using two continuous streams of data, is 4, and the number of other cases, each of which using two code keys, is 12. Therefore, the combination addition is selectively performed in some of the above cases.

For example, three combinations can be added in Table 7, so that it is assumed that only successive numbers are selected from combinations of three continuous data streams. In other words, the order of "Streaming Data1, Streaming Data2 and Streaming Data3", "Streaming Dataflow 2, Streaming Data3, and Streaming Data4" or "Streaming" is considered to be the order. Data Stream3, Streaming Data4, and Streaming Data1 "is selected. In fact, the data stream numbers are fixed in ascending numerical order, so that the order "Streaming data3, Streaming data4 and Streaming data" can be considered "Streaming data1, Streaming". Data Stream3 and Streaming Data4 "for convenience of description.

If a combination employing a single code key is added, the added combination may be {Code Key, (Streaming Data1, Streaming Data2, Streaming Data3)}, {Code Key, (Streaming Data Streaming 2, Data Streaming 3, Data Streaming 4)} or {Code Key, (Data Streaming 1, Data Streaming 3, Data Streaming 4)}, as shown in the following Table 11:

Table 11

<table> table see original document page 43 </column> </row> <table> <table> table see original document page 44 </column> </row> <table>

In Table 11, the added combination is denoted by a shaded part. And if a combination employing two code keys is added, the added combination can be [{Code Key, Streaming Data1}, {Code Key, (Streaming Data2, Streaming Data3 )}], [{Code Key, Continuous Data Stream2}, {Code Key, (Streaming Data3, Streaming Data4)}], and [{Code Key, Streaming Data1} , {Code Key, (Streaming Data3, Streaming Data4)}], as represented by the following Table 12:

Table 12

<table> table see original document page 44 </column> </row> <table> <table> table see original document page 45 </column> </row> <table>

In Table 12, the added combinations are denoted by the shaded parts.

In the meantime, as another example, two combinations can be added to Table 10, so that only successive numbers are considered to be selected from combinations of three continuous data streams. In other words, it is assumed that the orders "Streaming data1, Streaming data2 and Streaming data3", and "Streaming data2, Streaming3 and Streaming4" are selected. In the case of adding a specific case of a combination employing a single code key, {Code Key, (Streaming Data1, Streaming Data2, Streaming Data3)}, and { Code, (Streaming Data2, Streaming Data3, Streaming Data4)} can be added. In the case of adding another case of a combination employing two code keys, [{Code Key, Streaming Data1}, {Code Key, (Streaming Data2, Streaming Data3)}] and [{Code Key, Streaming Data2}, {Code Key, (Streaming Data3, Streaming Data4)}] can be added. The above combinations can be shown in the following Tables 13 and 14:

Table 13

<table> table see original document page 46 </column> </row> <table> <table> table see original document page 47 </column> </row> <table> <table> table see original document page 48 < / column> </row> <table>

In Tables 13 and 14, the added combinations are denoted by the shaded parts.

In the meantime, another embodiment of the present invention considers a grouping of continuous data streams as a rational method for limiting the number of combinations between a code key and a continuous data stream, and a detailed description thereof will be given below. .

If four antennas are to be used for MIMO technology, individual antennas must set up unique channel environments that are independent of each other in order to implement an optimal state. For this purpose, individual antennas are physically spaced from each other.

However, continuous data streams are grouped for several reasons when the antennas are actually used, so that antennas contained in each group can correlate with each other.

Figures 10A-10C show a variety of methods for grouping multiple antennas in various ways.

Figure 10A shows an ideal case in which four antennas set up independent channels without any grouping. However, four antennas are spaced apart at a predetermined distance so that a transmitter or receiver can have insufficient space to set up independent channels. Specifically, it is difficult for the structure of Figure 10A to be applied to a mobile terminal.

In order to solve the above problem, the structure of figure 10B has been widely used. In this structure of FIG. 10B, two antennas are grouped, antennas of each group have related channels, and other antennas of different groups have independent channels. And, another structure of figure 10C can also be used to solve the above problem. In this structure of Figure 10C, two antennas are grouped by a cross polarity diversity (CPD) scheme, antennas of one group are horizontally polarized, and antennas of the other group are vertically polarized.

In another example of antenna array, if a total of 4 antennas are used, the channel conditions of the two antennas are stably measured, and the channel conditions of the remaining two antennas are unstable, so that an error frequently occurs in the two remaining antennas. In this situation, antennas with a stable channel condition are grouped, and the other antennas with an unstable channel condition are grouped so that the four antennas are grouped two by two.

In the above, if the antennas are clustered and limited, continuous data streams corresponding to the antennas are also limited, and it can be seen that predetermined continuous streams of data are clustered.

Therefore, one embodiment of the present invention provides a method for limiting the number of all combinations between a code key and a continuous stream of data. In more detail, the aforementioned embodiment limits the number of continuous streams of data, each of which transmits a single code key, as shown in Tables 4 and 5, and continuous streams of data in groups. And, if a single code key is transmitted via data streams corresponding to the number of data streams contained in a single group, the aforementioned embodiment controls the only code key to be transmitted via data streams. contained in a single group so that the number of combinations between a code key and a continuous stream of data is reduced. A detailed description of the above mentioned embodiment will be given below.

In a detailed example, it is considered that a first data stream 1 and a second data stream 2 form a single group, and a third continuous data stream 3 and a fourth data stream 4 form another group. group. In this case, according to one embodiment of the present invention, if a single code key is transmitted via two continuous streams of data, this code key may be allocated to only one group, and all limited combinations are shown in the following Table 15:

Table 15

<table> table see original document page 49 </column> </row> <table> <table> table see original document page 50 </column> </row> <table>

Referring to Table 15, if a maximum number of code keys is 1, the number of available combinations is 6. If a maximum number of code keys is 2, the number of available combinations is 11, so a total of 17 combinations be made available.

Therefore, as described above, if a single code key is transmitted over a maximum of 2 continuous data streams, multiple data streams are grouped together two by one and the single code key is transmitted over two streams. Data streams, the present invention allows the single code key to be transmitted by means of only streams of data contained in the same group. In this case, all key code - continuous data stream combinations can be denoted by a maximum of 5 bits (24 = 16 <17 <25 = 32).

In the meantime, according to another embodiment of the present invention, if the combination of a code key and a data stream is limited and at the same time several code keys are transmitted in conjunction with Table 15, the above This mode allows code keys to be transmitted through continuous streams of data from different groups or allows code keys to be transmitted through continuous streams of data from the same group, so that the number of all key combinations of code - continuous data flow can be further reduced. A detailed description of the above mentioned embodiment will be given below.

Referring to Table 15, if multiple code keys are transmitted to further reduce the number of bits required to indicate all combinations, that is, if two code keys are transmitted, individual code keys are transmitted through streams. data streams from different groups or from other streams of data from the same group, so that they are transmitted across different channel environments, resulting in the acquisition of a diversity gain.

In this case, the aforementioned case in which two code keys are transmitted through data streams from different groups may indicate that data streams with the same or similar channel environments in their groupings are grouped into one. only group. The other case in which two code keys are transmitted through continuous streams of data from the same group may indicate that continuous streams of data with different channel environments in their groupings are grouped into a single group. In other words, if two code keys are transmitted through different channel environments, they are transmitted via continuous data streams from different groups or other continuous streams of data from the same group according to a method of streaming data grouping.

Referring to Table 15, if a first data stream 1 and a second data stream 2 configure a single group, and a third data stream 3 and a fourth data stream 4 configure another single group, the above in which case two code keys are transmitted via continuous data streams from different groups can be denoted by the following Table 16:

Table 16

<table> table see original document page 51 </column> </row> <table> <table> table see original document page 52 </column> </row> <table>

In Table 16, the bounded parts are denoted by the shaded parts.

Referring to Table 16, if a maximum number of code keys is 1, the number of all combinations is 6. If a maximum number of code keys is 2, the number of all combinations is 9, so that a total of 15 combinations are made available. Therefore, in the above example of the present invention, a maximum of 4 bits (23 = 8 <15 <24 = 16) is required to indicate all combinations of a code key and a continuous data stream.

In the meantime, the aforementioned case in which the two code keys are transmitted through continuous streams of data from the same group can be denoted by the following Table 17:

Table 17

<table> table see original document page 53 </column> </row> <table>

In Table 17, the bounded parts are denoted by the shaded parts. Referring to Table 17, if a maximum number of code keys is 1, the number of all combinations is 6. If a maximum number of code keys is 2, the number of all combinations is 7, so that a total of 13 combinations are made available. Therefore, in the above example of the present invention, a maximum of 4 bits (23 = 8 <15 <2 "4 = 16) is required to indicate all combinations of a code key and a continuous data stream.

In the meantime, another embodiment of the present invention provides a method for limiting the number of code keys or data streams in conjunction with Tables 4 and 5. In more detail, the aforementioned embodiment limits the number of streams Tx data stream through which a single code key is transmitted, groups continuous data streams using Tables 15 - 17, allows at least two continuous data streams to be transmitted via at least two code keys and allows a receiver to perform the SIC scheme related to figure 7 so that it reduces the number of all key code - data stream combinations and improves decoding performance of an Rx signal.

In other words, with respect to FIGS. 7, 8A and 8B, if several continuous data streams (for example, two continuous data streams) are transmitted, and the continuous individual data streams have independent code keys, one signal. Rx that receives independent code keys can improve the decoding performance of each code key. However, if a single code key is distributed to the individual streams of data and then transmitted, a receiver cannot realize the SIC scheme.

Therefore, as long as at least two streams of data pass at least two code keys, the following Table 18 is made:

Table 18

<table> table see original document page 54 </column> </row> <table> <table> table see original document page 55 </column> </row> <table>

Referring to Table 18, if a maximum number of code keys is 1, the number of all code key - data stream combinations is 4. If a maximum number of code keys is 2, the number of all key code - data stream combinations are 11, so a total of 15 combinations are made available. Therefore, in the above example of the present invention, a maximum of 4 bits (23 = 8 <15 <24 = 16) of a control signal is required to indicate all combinations of a code key and a continuous data stream.

The aforementioned embodiments of the present invention consider that a single user MIMO communication system is used. However, if you consider a multi-user MIMO communication system, a condition between a code key and a continuous stream of data may change to another condition.

Another embodiment of the present invention provides a method for rationally limiting the number of all key code - data stream combinations in consideration of the aforementioned multiuser environment, and a detailed description thereof will be given below.

In order to gain a multi-user diversity gain from the multi-user MIMO communication system, a search process for users with or- ganic channels relative to each other is important. If a single user uses all streams of data, a single user MIMO system is designed so that the user cannot acquire a multiuser diversity gain. In order to implement the multi-user MIMO communication system, it is preferable that the number of continuous streams of data that can be used by each user be reduced.

This embodiment of the present invention limits the number of all key code - data stream combinations to effectively acquire a multiuser diversity gain from the single user or multiuser MIMO communication system. For convenience of description, a maximum number of continuous data streams is considered to be 4 and a maximum number of code keys to be 2 in the following examples.

Preferably, the multi-user MIMO communication system may select users with orthogonal channels relative to each other from among several users. However, in fact, there is a low probability of selecting only orthogonal users. The multiuser MIMO communication system has a high probability of selecting users with orthogonal channels relative to each other so that it can be operated more stably.

Figure 11 shows the number of streams of data available from a user in a multiuser MIMO communication system.

Referring to Figure 11, if a single user uses at least two continuous streams of data, another limitation is applied in a user selection process.

In other words, if a single user uses two or more streams of data, channels that pass through all streams of data from a corresponding user must be orthogonal to each other. The user who uses two or more continuous streams of data must be selected from several users who satisfy the following condition. Subsequently, a process to search for specific users with orthogonal channels relative to each other among matching users must be performed. In this case, a variety of methods can be used as a final selection, for example, a Maximum Sum Rate method.

In more detail, as shown in Figure 11, if a first user 1 uses a first data stream 1 and a second data stream 2, two channels of the first user 1 employing the first and second data streams 1 and 2 must be orthogonal to each other, and the first user 1 must be selected from users who satisfy the aforementioned orthogonal condition. A second user 2 channel employing a third continuous data stream 3 should be orthogonal to a third user channel employing a fourth continuous data stream 4, the process for selecting users that satisfy the above condition. more difficult than in another case where all users use a single continuous stream of data. Therefore, in order to support the above case in which a single user uses several continuous streams of data, the above operation can easily be performed on the condition that there are many more users.

Therefore, in order to easily select desired users in the multiuser MIMO communication system, one embodiment of the present invention allows a single user to use only one continuous stream of data to limit the number of all key code - stream combinations. continuous data. In this case, available combinations between a code key and a continuous stream of data can be represented by the following Table 19:

Table 19

<table> table see original document page 57 </column> </row> <table>

As can be seen from Table 19, in order to easily select a desired user in the multiuser MIMO communication system, the aforementioned embodiment of the present invention limits the number of key code - data stream combinations so that a single user can use only a continuous stream of data. In this case, the number of all combinations is 4, and can be denoted by a maximum of 2 bits (21 <4 <2 ^ 2 = 4).

In the meantime, with respect to Table 19, the above-mentioned embodiment of the present invention allows a single user to use only one continuous stream of data, so that the multiuser MIMO communication system can easily select an orthogonal channel between users, however, it is perceived It is assumed that a maximum peak speed of each user may suffer losses.

Therefore, in order to solve the above problem, another embodiment of the present invention allows a single user to use multiple streams of data, but it allows individual streams of data to use different code keys. A detailed description of the above mentioned embodiment will be given below.

In more detail, as long as a single user uses two continuous streams of data, each user's maximum peak speed may be higher than that of the case shown in Table 19. Also, the above-mentioned embodiment of the present invention enables Individual streams of data use different code keys and apply the SIC scheme to an Rx signal received at a receiver so that it can improve decoding performance.

In this situation, all combinations between a code key and a continuous data stream can be represented by the following Table 20:

Table 20

<table> table see original document page 58 </column> </row> <table>

Referring to Table 20, the number of all key code combinations - continuous data stream is 6, and can be denoted by a maximum of 3 bits (22 = 4 <6 <23 = 8).

In the meantime, with respect to Tables 19 and 20, the above-mentioned embodiments of the present invention have the aforementioned advantages and disadvantages. A multiuser MIMO communication system according to another embodiment of the present invention accommodates a key code - data stream combination in which advantages and disadvantages are applied, and may selectively use the combination according to various situations. .

In this case, all combinations between a code key and a continuous data stream can be represented by the following Table 21: Table 21

<table> table see original document page 59 </column> </row> <table>

In this case, as can be seen from Table 21, if a single user uses a single stream of data, 4 combinations are made available. If a single user uses two continuous streams of data, 6 combinations are made available so that a total of 10 combinations are made available. Therefore, the above combinations can be denoted by a maximum of 4 bits (23 = 8 <10 <24 = 16).

The aforementioned embodiments have disclosed a logical method for reducing the number of combinations between a code key and a continuous stream of data.

In the meantime, one embodiment of the present invention will disclose a method for further reducing the number of key code - data stream combinations in consideration of an Rx scheme and the receiver Rx performance, and a detailed description thereof will be given. follow.

If a SIC-based receiver is used as a receiver of the present invention and there are several code keys, overall system performance may change according to the order of protection of the code keys. Therefore, the order of the code keys in each combination must be considered.

First, as shown in Figure 5A, if a maximum number of data streams is 4 and a maximum number of code keys is 2, the following combinations are provided.

If the number of antennas is 4, ie if a maximum number of data streams is 4, a maximum number of code keys is 2. In this case all code key combinations - available data stream are shown in the following

Tables 22 and 23: Table 22

<table> table see original document page 60 </column> </row> <table> Table 23

<table> table see original document page 61 </column> </row> <table> <table> table see original document page 62 </column> </row> <table> <table> table see original document page 63 < / column> </row> <table> <table> table see original document page 64 </column> </row> <table>

Table 22 shows examples of individual combinations when the number of code keys is 1. Table 23 shows examples of individual combinations when the number of code keys is 2.

The order of the code keys in Tables 22 or 23 is denoted by successive numbers. The code key number indicates a decoding order when a receiver uses the SIC-based receiver. Subsequently, code key 1 is first decoded, as shown in Figure 7, an interference signal related to code key 1 is removed from signal Rx, and then a code key 2 is decoded.

In other words, the antenna mapping operation changes according to the order of data streams as each data stream is remapped to the antenna. Also, if a precoding method is used, the antenna mapping operation changes according to the precoding order in conjunction with a corresponding weighting vector. Therefore, continuous data streams have a fixed order, so the order of continuous data streams in a combination must also be indicated.

As you can see from Tables 22 and 23, if the number of code keys is 1, the number of combinations is 15. If the number of code keys is 2, the number of combinations is 50, so that a total of 65 combinations are required. Therefore, in order to allow all combinations without any restrictions, provided that a maximum number of code keys is 2 and a maximum number of continuous data streams is 4, a maximum of 7 bits is required (26 = 64 <65 <27 = 128).

In the meantime, as shown in Figure 5B, all code key - data stream combinations provided when a maximum number of data streams is 2 and a maximum number of code keys is 2 are as follows.

As shown in Figure 5B, if the number of antennas is 2, that is, if a maximum number of continuous data streams is 2, a maximum number of code keys is 2. All cases of individual combinations are shown. in the following Table 24:

Table 24

<table> table see original document page 65 </column> </row> <table> Table 24 shows all examples of individual combinations provided when the number of code keys is 1 or 2.

As shown in Table 14, if a maximum number of data streams is 2 and a maximum number of code keys is 2, a total of 5 code key combinations - data streams is required. In this case, to allow all combinations without any restrictions, provided that the maximum number of continuous data streams is 2 and the maximum number of code keys is 2, a maximum of 3 bits is required ( 22 = 4 <5 <23 = 8). However, the above case can be considered as a subset of the case in which a maximum of 4 continuous data streams, shown in Tables 22 and 23, is used. Therefore, if the aforementioned case in which a maximum of 4 continuous data streams is used can be effectively indicated, it is clear that this case can also be applied to another case in which a maximum of 2 continuous data streams is used.

In the above, the above case in which the maximum number of continuous data streams requires a small number of bits to independently indicate the combination of a code key and a continuous data stream so that it is left out of range. consideration. Therefore, the following embodiment of the present invention will disclose a method for effectively indicating all key code - least bitstream data stream combinations based on the above case in which a maximum of 4 continuous data streams is used. If the combination of a code key and a continuous data stream can be denoted with fewer bits, the Tx efficiency of a control signal can be improved.

As stated previously, if a given constraint condition between a code key and a continuous data stream is that a maximum number of continuous data streams is 4 and a maximum number of code keys is 2.65 combinations between the code key and streaming data is made available. In order to indicate all 65 combinations without any restrictions, a total of 7 bits is required.

One embodiment of the present invention will disclose a method for limiting all combinations of a code key and a data stream under consideration to an Rx scheme and a receiver Rx performance so that it can reduce the number of pieces of information. which indicates combinations used between all combinations.

Figure 12 shows a simulation result that indicates a difference in system throughput between a first case, in which only one code key is used, and a second case, in which two code keys are used, on condition that that there are several continuous streams of data.

In Figure 12, "SCW" is an abbreviation for Single Code Key, "MCW" is an abbreviation for Multiple Code Keys. "MMSE" indicates a specific case in which a receiver based on minimum mean square error ("MMSE") is used on a receiver. "MMSE + SIC" indicates that a specific receiver that can perform interference cancellation by applying the SIC scheme to the resulting MMSE signal is used on a receiver. "lor / loc" on a horizontal geometry axis indicates the ratio of a Tx energy of a B-Node to an interference energy. The ratio of energy Tx to interference energy can be calculated by a SINR1 and is physically similar to the SINR.

A consideration of the detailed simulation of Figure 12 is as follows. Two Tx antennas and two Rx antennas are used, an MCS scheme with nas on 3GPP TR 25.892 is used, and the Antenna Speed Control (PARC) scheme is used more like the MIMO scheme. ITU's proposed "Pedestrian B" model is considered to be used as a simulation channel, and a mobile terminal has a speed of 3 km / h. And, considering an OFDM scheme is used as a transmission scheme, the FFT length is 1,024, the number of subcarriers actually used for a 10 MHz bandwidth is 600, and the size of a cyclic prefix. (CP) is 74.

As can be seen from the result of Figure 12, in the case of two continuous data streams transmission, a first case, in which the two continuous data streams are distributed to two code keys, performs well above that of a second case, in which the two continuous streams of data are transmitted through a single code key. The above result has the same result in light of the number of continuous data streams or code keys. If the above result is generalized, the following result can be acquired. In other words, if multiple streams of data are used, it is preferable that multiple code keys instead of a single code key are used to increase overall system performance. Therefore, if multiple streams of data are used to limit the number of all combinations between a code key and a stream of data, one embodiment of the present invention provides a method for limiting a combination that allows a single key. use all streams of data.

In more detail, as described above, the above-mentioned embodiment, in which a maximum of 4 continuous data streams is used and a maximum of 2 code keys is used, can allow desired data to be transmitted by two keys. when the key code - data stream combination has two or more data streams.

The combination of a code key and a data stream according to the aforementioned embodiment of the present invention may be represented by the following Table 25:

Table 25 <table> table see original document page 68 </column> </row> <table> <table> table see original document page 69 </column> </row> <table> <table> table see original document page 70 </column> </row> <table> <table> table see original document page 71 </column> </row> <table>

Refer to Table 25, as long as multiple code keys can be available when multiple streams of data are used and there are restrictions to allow multiple code keys to be used instead of a single code key, the number of combinations is 4 when a maximum number of code keys is 1 and the number of combinations is 50 when a maximum number of code keys is 2, so a total of 54 combinations is required. These 54 combinations can be denoted by a maximum of 6 bits (2 "5 = 32 <54 <2" 6 = 64).

A more preferred embodiment of the present invention provides a method for setting the decoding order based on the SIC scheme to reduce the number of all combinations.

Figures 13A - 13C show the results of the performance simulation of a receiving station according to the order of the SIC decoding.

It can be seen that all combinations shown in Table 25 include a specific part that indicates the order of decoding when the SIC scheme is used on a receiver. In order to indicate the decryption order of the code keys and the associated SIC receiver, the combination of a code key and a continuous stream of data is symmetrically repeated.

For example, if two data streams (ie data stream 1 and data stream 2) are used, the first combinations (Code Key, Data Stream 1) and (Code Key 2, Data Stream data2) exist and the second combinations (Code Key, Streaming Data2) and (Code Key2, Streaming Data1) also exist. The decoding orders of the first combinations are symmetrically different from those of the second combinations. The result of the simulation that indicates a performance difference between the first and second combinations is shown in figure 13A. Figure 13B shows a case in which three continuous streams of data are used, and Figure 13C shows another case in which four continuous streams of data are used. The simultaneous environments of figures 13A - 13C are different in number of antennas, and the remaining parts of figures 13A - 13C are the same as those of figure 12. In more detail, figure 13A shows two antennas, figure 13B shows three antennas, and figure 13C shows four antennas, and the remaining different parts of the number of antennas are the same as those of figure 12.

In order to analyze the simulation result, the case of figure 13C, which illustrates a case performance employing 4 continuous data streams, will be described below.

In Figure 13A, "Max" is a specific case in which all original combinations indicating the SIC decoding order are included. "(12, 34) L1, L2 first" is a specific case in which data streams 1 and 2 (or layers 1 and 2) L1 and L2 are assigned to a first code key 1, data streams 1 and 2 of the first code key 1 are first decoded during SIC decoding when data streams 3 and 4 (or layers 3 and 4) are used for a second code key 2 and then data streams 3 and 4 of a second code key 2 are decoded. Thus, "(34, 12) L3, L4 first" is a specific case in which data streams 3 and 4 are assigned to a first code key 1, data streams 1 and 2 are assigned to a second code key 2, data streams 3 and 4 corresponding to the first code key 1 are first decoded and then the other data streams 1 and 2 corresponding to the second code key 2 are decoded .

As can be seen from the result of figure 13C, in the case of (12, 34) or (34, 12) in which two continuous streams of data are assigned to each code key, there is almost no difference in performance between the case of (12, 34) and the other case of (34, 12).

Also, in the case of (1, 234) or (234, 1) in which a single data stream is assigned to a single code key and three data streams are assigned to other data streams, There is almost no difference in order between the case of (1, 234) and the case of (234, 1).

In another aspect, the case in which two continuous streams of data are assigned to each code key performs better than that of the other case in which a single continuous stream of data is assigned to a single code key and three contiguous streams. Numbers of data are assigned to other continuous streams of data. Although the above case, in which two continuous streams of data are assigned to each code key, performs slightly less than that of the other case in which all cases are allowed, it is clear that the performances of the above two cases are poor. very close to each other. Therefore, in terms of performance, it is preferable that the SIC decoding order be fixed only in a predetermined order, and that a maximum of 2 code keys are selected by a single code key.

Figure 13B shows different performances when three continuous data streams are used, in which a single continuous data stream is assigned to a single code key and two continuous data streams are assigned to the other code key. In this case, it is more preferable that the code key composed of the two continuous data streams is decoded after the single continuous data stream has been decoded, resulting in the implementation of superior performance.

Figure 13A shows performance when a total of 2 continuous streams of data are used, in which a single continuous stream of data is assigned to each code key. In this case, it can be seen that there is almost no difference in performance between decoded code keys, regardless of the decoding order of the code keys.

The following three results are gained by the performances of figures 13A - 13C. According to a first result, the decryption order of the SIC receiver is fixed so that code key 1 is first decoded and then code key 2 is decoded.

According to a second result, if the number of data streams assigned to the first code key 1 is asymmetric to the number of data streams assigned to the second code key 2, a code key with the least number of data streams data between the first and second code keys 1 and 2 is first decoded. For example, if the number of all combinations is 3, one code key has a single data stream and the other code key has two data streams, the code key consisting of only one data stream being first decoded. For this purpose, a single data stream is assigned to the first code key 1 and two data streams are assigned to the second code key 2.

According to a third result, a maximum of 2 continuous data streams is assigned to a single code key.

In more detail, according to this embodiment, in which a maximum of 4 continuous data streams and a maximum of 2 code keys are used, it is considered that the SIC receiver decoding order in all combinations shown in Tables 22 and 23 is fixed, the allocation process has a symmetrical structure to indicate that the SIC decoding order is removed, and the SIC receiver first decodes the first code key 1 and then decodes the second key. Namely, the term "SIC decoding order" used in the aforementioned embodiment of the present invention is indicative of the decoding order of the individual code keys when the SIC receiver is used.

Also, if there are a total of 3 continuous data streams, the aforementioned embodiment considers only one specific case, in which a single continuous data stream is assigned to a first code key 1 and two continuous data streams are assigned. second code key 2. And, if there are a total of 4 continuous data streams, the aforementioned embodiment considers only one specific case, in which two continuous data streams are assigned to a first code key 1 and the two remaining streams of data are assigned to a second code key 2.

A detailed example associated with the above mentioned embodiment is shown in the following Table 26:

Table 26

<table> table see original document page 74 </column> </row> <table> <table> table see original document page 75 </column> </row> <table> <table> table see original document page 76 < / column> </row> <table> <table> table see original document page 77 </column> </row> <table>

Therefore, a detailed embodiment of the present invention has a total of 36 cases, which are denoted by a maximum of 6 bits (25 = 32 <36 <26 = 64). In each case, the SIC decoding order is fixed, a single code key has a maximum of 2 continuous streams of data, and a code key with the least number of continuous streams of data is first decoded in the case of one stream. asymmetric continuous data In light of the number of bits of control information that indicates all combinations, the aforementioned case has a 1-bit gain compared to the cases shown in Tables 22 and 23.

In the meantime, the method of reducing the number of cases of the above (unreadable) is applied in the above-mentioned modality. In other words, if multiple data streams are used, multiple code keys are used, a single code key has a maximum of 2 data streams, and a code key with fewer data streams is used. fixed in a first code key, so that the number of all combinations can be limited.

As long as the SIC-based receiver is used on a receiver, multiple code keys are used when multiple streams of data are used, and a single code key has a maximum of 2 streams of data. In the case of an asymmetric data stream, a code key with the least number of data streams is first decoded, and the SIC decoding order is fixed, so that the number of all combinations can be limited.

A detailed example associated with the above description is shown in the following Table 27:

Table 27

<table> table see original document page 77 </column> </row> <table> <table> table see original document page 78 </column> </row> <table> <table> table see original document page 79 < / column> </row> <table>

Therefore, a detailed embodiment of the present invention has a total of 25 cases. In each case, multiple code keys are used when multiple continuous data streams are used, and a single code key has a maximum of 2 continuous data streams. And in the case of an asymmetric data stream, that is, if individual code keys use different numbers of data streams, a code key with the least number of data streams is assigned to a first code key.

Also, one embodiment of the detailed description of the present invention has a total of 25 cases. In each case, if multiple streams of data are used, multiple code keys are used in consideration of the uses of the SIC decoder contained in a receiver, the SIC decoding order is fixed, and a single code key has to be set. a maximum of 2 continuous streams of data. And, in the case of an asymmetric data stream, that is, if individual code keys use different numbers of continuous data streams, a code key with the least number of continuous data streams is first decoded. Therefore, the number of cases is 25, so it must be denoted by a maximum of 5 bits (24 = 16 <25 <25 = 32). In this case, in light of the number of control information bits indicating all combinations, the above case has a 2 bit gain compared to the cases shown in Tables 22 and 23.

As described above, each continuous stream of data has a plurality of combinations. But, the present invention aims to reduce the number of combinations for each continuous stream of data.

Figure 14 shows the result of simulating the performance of a receiving station when the number of all combinations of a code key and a continuous data stream is limited to a specific number of combinations that can be indicated by a given bit number.

In more detail, Figure 14 shows the simulation result in which 4 Tx antennas and 4 Rx antennas were used, ie a maximum number of continuous data streams is 4. Other simulation considerations other than the number of antennas are the same as those. of figure 12.

A detailed description of the simulation result of figure 14 will be given below. If the number of all combinations is determined in Tables 22 and 23, this case is denoted by "max". If only one combination is allowed for each continuous stream of data, the number of all combinations is 4, 4 combinations being denoted by 2 bits, as represented by "bit2". If two combinations are allowed for each stream of data, 8 cases are denoted by 3 bits, as represented by "bit3". If 4 combinations are allowed for each stream of data, 16 cases are denoted by 4 bits, as represented by "bit4".

As can be seen from the simulation result in Figure 14, if only one combination is allowed for each continuous stream of data, this case has a performance almost similar to that of another case in which all combinations are rendered disjoint. - available.

As can be seen from the result of the simulation of figure 14, although a combination selected to reduce combinations to the corresponding number of bits is arbitrarily selected, there is almost no difference in performance between this case and the above case in which all combinations are made available. Therefore, in order to reduce the number of cases in each combination, it is more preferable that the number of cases in each combination be reduced to up to 4 combinations.

In a detailed example associated with the above description, if a maximum of 4 continuous data streams and a maximum of 2 code keys are used, the "2bit" case that can be denoted by a minimum of combinations can be represented by the following Table. 28:

Table 28

<table> table see original document page 81 </column> </row> <table>

Therefore, a detailed embodiment of the present invention has a total of 4 cases. In each case, if multiple data streams are used, multiple code keys are used, a single code key has a maximum of 2 data streams, a code key with the least number of data streams is set to a first code key in the case of an asymmetric data stream, each data stream using only one combination.

Also, a detailed embodiment of the present invention has a total of 4 cases. In each case, if multiple streams of data are used in consideration of a specific case in which a receiver uses the SIC decoder, several code keys are used, the SIC decoding order is fixed, a single code key has a bad - For up to 2 continuous data streams, a code key with the least number of continuous data streams is first decoded in the case of an asymmetric continuous data stream, and only one continuous data stream is allowed for each continuous data stream. The total number of cases is 4, so 4 cases must be denoted by a maximum of 2 bits (21 = 2 <4 <22 = 4). In this case, in light of the number of bits of control information that indicates all combinations, the above case has a gain of 5 bits compared to the cases shown in Tables 22 and 23.

In the meantime, the "3bit" case, among other detailed examples, should select two combinations for each continuous data stream, and the "4bit" case should select four combinations for each continuous data stream. The aforementioned examples are well known to those skilled in the art, so that their detailed descriptions are omitted for convenience of description. In this case, a process to select a combination of a fixed number can be arbitrarily executed. As a result of the simulation, although the combination is arbitrarily selected, there is almost no difference in performance.

In the meantime, considering a specific case in which a HARQ (Hybrid ARQ) scheme is used in the aforementioned combination, the addition of a combination may also be considered. If the number of code keys is 2, one code key has an error, and the other code key has no error, the number of retransmitted code keys being only one. If a chase matching technique, which was widely used for HARQ, is used for relaying, two code keys must be relayed without any modification from the first transmission. Therefore, relayed code keys must be transmitted through one or two continuous streams of data. A detailed description of this will be given below.

Two code keys are considered to be transmitted via three continuous streams of data during a first transmission. Also, one of the two code keys is considered to have an error and the other has no error. In particular, the relayed code key is considered to be only a first code key, so that it is transmitted through only one continuous stream of data. The case in which a single code key is transmitted through a single stream of data is contained in an original combination so that this case can be made available.

However, as another example, if a first code key has no error and a second code key has an error, a relayed code key is only a second code key and must be transmitted via two continuous streams. of data.

Moreover, the case in which a code key is transmitted via two continuous streams of data is not contained in the original combination. In order to relay a desired code key from the first transmission without any change, a combination in which a single code key is mapped to two continuous streams of data can also be added as needed. The above case is shown in the following Table 29:

Table 29

<table> table see original document page 82 </column> </row> <table> <table> table see original document page 83 </column> </row> <table>

The aforementioned embodiments of the present invention have disclosed a variety of methods for minimizing the number of key code streams - data streams among all available combinations according to the number of key code streams and data streams ( or layers). A method for allowing the combination to effectively process data under a given condition and for transmitting a signal will be described below.

As described above, a general wireless communication system performs channel coding to reliably transmit data. This channel coding indicates that a transmission encodes the Tx information using an early error correction code so that a channel error can be corrected by a receiver. The receiver demodulates a signal Rx1 decodes the early error correction code and retrieves the Tx information. In this decoding process, the Rx signal error caused by the channel is corrected.

An example of the early error correction code is a turbo code. The turbo code includes at least two recursive systematic convolution encoders and an interconnector that connects between at least two recursive systematic convolution encoders. The larger the data block, the better the turbo code performance. A real communication system divides a predetermined size data block into several smaller sized data blocks and encodes the split blocks so that it is really convenient to implement the actual communication system. These smaller sized data blocks are called code blocks. The early error correction coding process is performed on units of a predetermined size code block, mapped to wireless resources, and then transmitted to a destination.

If wireless resources are mapped after channel coding is performed in units of a code block by the MIMO communication system, spatial multiplexing is required. Individual MIMO channels are independent of each other. If spatial multiplexing of code blocks is performed for multiple Tx antennas, transmission efficiency can be improved.

Therefore, a method for effectively transmitting channel-encoded data via multiple Tx antennas is required.

Therefore, one embodiment of the present invention provides a method for effectively transmitting data for spatial multiplexing consideration by the MIMO communication system, and a detailed description thereof will be given below.

A wireless communication system can be based on an Orthogonal Frequency Division Multiflexion (OFDM) scheme. This OFDM scheme uses several orthogonal subcarriers. The OFDM scheme uses orthogonality between an Inverted Fast Fourier Transform (IFFT) and a Fast Fourier Transform (FFT). The transmitter performs the IFFT on the data and transmits the resulting IFFT data. The transmitter uses IFFT to combine multi-subcarriers. In order to separate the multi-subcarriers from each other, the receiver uses the FFT corresponding to the multi-subcarriers. The OFDM scheme reduces receiver complexity in frequency selective fading environments of a broadband channel, uses different subcarrier channel characteristics, and performs selective scheduling in a frequency domain, thereby increasing spectral efficiency. The Orthogonal Frequency Division Multiple Access (OFDMA) scheme is an OFDM scheme-based multiple access scheme. Under the OFDMA scheme, different subcarriers are assigned to multiple users so that the efficiency of wireless resources increases.

Figure 15 is a block diagram illustrating a wireless communication system.

The wireless communication system has been widely used to provide a variety of communication services, eg voice or packet data.

Referring to Fig. 15, the wireless communication system includes a user equipment (UE) 10 and a base station (BS) 20. The user equipment (UE) 10 may be fixed or mobile. User equipment (UE) may also be called a Mobile Station (MS), a User Terminal (UT), a Subscriber Station (SS), or a wireless device. Base station (BS) 20 may be a fixed station communicating with user equipment (UE) 10, or may also be referred to as a B-Node, Base Transceiver System (BTS) or a Access (AP). A single base station (BS) 20 can have one or more cells.

The term "downlink" is indicative of a communication path from base station (BS) 20 to user equipment (UE) 20. The term "uplink" is indicative of a communication path of user equipment ( UE) 10 to base station (BS) 20. A transmitter for downlink use may be some parts of base station (BS) 20, or a receiver may be some parts of user equipment (UE) 10 A transmitter for use on the uplink may be some parts of user equipment (UE) 10, or a receiver may be some parts of base station (BS) 20.

Fig. 16 is a block diagram illustrating a transmitter according to one embodiment of the present invention.

Referring to Figure 16, a transmitter 100 includes a CRC attachment unit 110, a code block segmentation unit 115, a channel encoder 120, an interleaver 130, a speed matching unit 140, a mapper 150, a layer mapper 160 and a precoding unit 170. The transmitter 100 includes Nt Tx antennas (190-1 ..... 190-Nt) (where Nt> 1).

CRC Attachment Unit 110 appends a cyclic redundancy check (CRC) code to detect an error in the input data. Code block segmentation unit 155 segments code added with CRC into code block units. In this case, the CRC code can be appended to the data and then segmented into units of the code block. Otherwise, the CRC code may be appended to the data in the code block units.

Channel encoder 120 performs channel coding on code blocks. The interleaver 130 performs interleaving of coded codes relative to the channel. Speed matching unit 140 adjusts the interleaved codes according to the amount of wireless resources used for actual transmission. Speed matching may be conducted by a drilling or repetition process. Mapper 150 maps code at matched speed to a symbol indicating a signal constellation location. An interleaver (not shown) may be located before mapper 150. Namely, the interleaver may be located between speed matching unit 140 and mapper 150.

Layer mapper 160 maps input symbols according to individual layers caused by spatial multiplexing. The resulting data mapped to each layer is called a continuous data stream. Precoding unit 170 precodes a continuous stream of input data according to the MIMO scheme based on transmit antennas (190-1 ..... 190-Nt).

In this case, several continuous streams of data are generated from a single code encoded with respect to the channel in the system of FIG. 16, so that this system is called a single code key (SCW) system.

Figure 17 is a block diagram illustrating a transmission according to another embodiment of the present invention.

Compared to the transmitter 100 shown in Fig. 16, the transmission of Fig. 17 generates several continuous streams of data by receiving at least one coded code relative to the channel, so that the system of Fig. 17 is called a multi-system. code keys (MCW).

Referring to Figure 17, the transmitter 200 includes a plurality of CRC attachment units (210-1 ..... 210-K) (wherein K> 1), a plurality of code block segmentation units. (215-1 ..... 215-K), a plurality of channel encoders (220-1 1 ..... 220-K), a plurality of interleavers (230-1 ..... 230-K ), a plurality of speed matching units (240-1, ..., 240-K), a plurality of mappers (250-1, ..., 250-K), a layer mapper 260, and a pre-coding unit 270. The transmitter 200 includes Nt Tx antennas (290-1 ..... 290-Nt) (where Nt> 1).

The CRC Attachment Unit (210-1 ..... 210-K) attaches a cyclic redundancy check (CRC) code to detect an error in the input data. Code Block Targeting Unit (215-1 ..... 215-K) Segments Code Added with CRC

in code key units. The channel encoder (220-1 ..... 220-K) performs channel coding on the code blocks. The interleaver (240-1 ..... 230-K) performs interleaving in the

coded codes relative to the channel. The speed matching unit (240-1 ..... 240-K) adjusts the interleaved codes according to the amount of wireless features used for actual transmission. Speed matching can be conducted by a drilling or repeating process. The mapper (250-1, ..., 250-K) maps the code at matched speed to a symbol indicating a signal constellation location. An interleaver (not shown) can be located between the speed matching unit (240-1 ..... 240-K) and the mapper (250-1 ..... 250-K).

Layer mapper 260 maps input symbols according to individual layers caused by spatial multiplexing. The resulting data mapped to each layer is called a continuous data stream. This continuous stream of data can also be called a layer. Precoding unit 270 precodes a continuous stream of input data according to the MIMO scheme based on transmit antennas (290-1, ..., 290-Nt).

Figure 18 is a block diagram illustrating a channel coding scheme according to one embodiment of the present invention.

Referring to Fig. 18, channel coding, interleaving, and velocity matching are performed in a single code block so that the single code block is transmitted via several continuous streams of data. The code block is a data block of predetermined size to perform channel coding. The code block can be the same size, and multiple code blocks can have different sizes.

Referring to Fig. 18, channel encoder 320 performs channel coding in an input code block. Channel encoder 320 may be a turbo code. The turbo code may include a recursive and convoluted systematic convolution encoder. The turbo code generates a systematic bit and a parity bit in bit units upon receipt of the input code block. In this case, a code rate is assumed to be 1/3, and a single systematic block S and two parity blocks P1 and P2 are generated. The systematic block is a set of systematic bits, and the parity block is a set of parity bits.

The interleaver 330 performs interleaving the coded code block with respect to the channel so that it reduces the influence of a burst error caused by the RF channel transmitter. Interleaver 330 can perform interleaving on systematic block S and each parity block P1 or P2, respectively.

Speed matching unit 340 adjusts the coded code block with respect to the channel according to the size of the radio resources. Speed matching can be performed in units of the coded code block relative to the channel. Or, the systematic block S and the two parity blocks P1 and P2 are separated from each other so that the velocity matching can be performed on each other.

A data transmitter method based on spatial multiplexing will be described below.

For convenience of description and a better understanding of the present invention, it is considered that data is transmitted by means of two continuous streams of data (ie two layers).

Systematic block S and two parity blocks P1 and P2 generated from a single code block are equally distributed to two continuous streams of data and then transmitted to a destination. In the event that the code block is equally distributed to two data blocks and then transmitted to the destination, a system can acquire spatial diversity, resulting in the best performance. Systematic block S is more important for decoding compared to the two parity blocks P1 and P2. So if systematic block S is transmitted to a continuous stream of data with a better channel condition, performance can be improved. In this case, if two continuous streams of data map to radio resources, a specific pattern can be used as needed.

Next, it is assumed that there are two or more blocks of code to be transmitted. In this case, three code blocks are assumed to be equally distributed to two continuous streams of data and then transmitted to a destination.

Figure 19 is a conceptual diagram illustrating data transmission according to one embodiment of the present invention.

Referring to Figure 19, two continuous streams of data (ie two layers) are distributed to a frequency domain over a single subframe, so that they are separated from each other in the frequency domain. A single subframe is indicative of a frequency domain that includes a plurality of resource blocks. A single resource block includes a plurality of subcarriers. For example, a single resource block might include 12 subcarriers. A single subframe is indicative of a time domain comprising two positions, each of which includes 7 OFDM symbols. However, the aforementioned description exemplarily defines the number of resource blocks, the number of positions and the number of OFDM symbols contained in the single subframe, so that the scope of the present invention is not limited to the above values. can also be applied to other examples.

A single block of code is equally mapped to two continuous streams of data. Radio resources allocated to the single code block are equally allocated to the two continuous streams of data. After the single code block has been mapped, the next code block is mapped by the same method as in the mapped code block. In this case, three blocks of code are evenly distributed up to two continuous streams of data and then mapped. In this case, an interval occupied in the temporal domain may be a minimum interval.

When using turbo code, a single code block is divided into a systematic block S and two parity blocks P1 and P2. Systematic block S and parity blocks P1 and P2 are equally distributed up to two continuous streams of data and then transmitted to a destination. The mapping of systematic block S and parity blocks P1 and P2 may have a specific pattern. Specifically, systematic block S is more important for error correction compared to parity blocks P1 and P2, so that systematic block S can be evenly distributed up to two continuous streams of data and then transmitted to a destination. . Therefore, the spatial diversity gain for system block S can be acquired, or system block S can be mapped to a continuous stream of data with a good channel condition.

The code block is distributed up to two continuous streams of data and then mapped. And, two continuous streams of data are transmitted via multiple antennas, so the gain in spatial diversity caused by the continuous stream of data is acquired. The code block is also mapped to two continuous streams of data so that the decoding delay caused by the transmission of continuous streams of data can be reduced.

When the code block is mapped to N streams of data (where N> 1 and N = even number), it can be mapped to N streams of data as well. If N is an odd number, the code block can be mapped equally evenly to the N streams of data.

Fig. 20 is a conceptual diagram illustrating a data transmission according to another embodiment of the present invention.

In more detail, Figure 20 shows an exemplary case in which a code block is distributed up to two continuous streams of data and then transmitted through the two continuous streams of data.

Referring to Figure 20, a first code block is mapped to one of the two continuous data streams, and a second code block is mapped to the other continuous data streams. A third block of code is mapped by two continuous streams of data.

When a single code block is mapped to a single continuous stream of data, a redundant code block may occur. In other words, when M code blocks (where M> 1) are mapped to N continuous data streams (where N> 1), the relationship between MeN values is not denoted by a multiple, as denoted by M = kxN + q (k = integer, 0 <q <N - 1). In this case, the code block q can be distributed up to N continuous streams of data and then mapped to them.

If a single code block includes a systematic block S and parity blocks P1 and P2, the systematic block S and parity blocks P1 and P2 can be mapped to a single continuous data stream according to a specific pattern.

Fig. 21 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention.

Referring to Fig. 21, a first code block and a second code block are mapped to two continuous streams of data according to a specific pattern. The first code block and the second code block cross each other in units of an OFDM symbol. A third block of code is mapped by two continuous streams of data.

If M code blocks are transmitted during L OFDM symbol intervals, the first code block is mapped to N continuous data streams during a "ceiling (L / M)" interval, and the second code block is mapped, "ceiling". (x) "can be a minimum integer greater than" x ". Symbols from a first OFDM symbol to the full OFDM symbol (L / M) -1 are completely filled with data, but the ceiling (L / M) -th OFDM symbol can be partially filled. Subsequently, the next block of code is mapped.

If a single code block includes systematic block S and parity blocks P1 and P2, systematic block S and parity blocks P1 and P2 can also be mapped with two continuous streams of data. The mapping of the systematic block S and the parity blocks P1 and P2 by the two continuous data streams can have a specific pattern.

Fig. 22 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention.

Referring to Figure 22, a first code block and a second code block are mapped to two continuous streams of data according to a specific pattern. The first code block and the second code block cross each other in units of a resource block. A third block of code is mapped by two continuous streams of data.

If a single code block includes system block S and parity blocks P1 and P2, system block S and parity blocks P1 and P2 may also be mapped with two continuous streams of data. Mapping of the systematic block S and the parity blocks P1 and P2 by the two continuous data streams can have a specific pattern.

Fig. 23 is a conceptual diagram illustrating a data transmission according to yet another embodiment of the present invention.

Referring to Figure 23, three blocks of code are mapped across all subframes. The three blocks of code are transmitted through two continuous streams of data. The three blocks of code can be mapped to up to two continuous streams of data according to a specific pattern.

In this case, 3 code blocks are mapped one by one in units of a resource block (that is, on a frequency axis), and the 3 code blocks can be mapped one by one in units of a symbol. OFDM (that is, on a time axis).

The aforementioned code block segmentation method and the data transmitter method using it will be described in detail below. For the better understanding of the present invention, an OFDM-based transmission / receiver data processing step will also be described in detail.

Fig. 24A is a block diagram illustrating a data processing method of a transmitter according to an OFDMA scheme. Fig. 24B is a block diagram illustrating a method of processing data from a receiver according to an OFDMA scheme.

Referring to Figure 24A, the transmitting station performs a modulation of a symbol mapping (also called a constellation mapping) in a bit stream for each user according to a Phase Shift Manipulation (QPSK) modulation scheme. Quadrature), 16 QAM (Quadrature Amplitude Modulation) or 64 QAM in step S11. By this symbol mapping, at least two bits are mapped to a symbol.

The bit stream is mapped to a data symbol. This data symbol is converted to a parallel data symbol by an S / P (Serial / Parallel) converter in step S12. By S / P conversion, the data symbol is converted to parallel symbols up to the number of subcarriers allocated to each user (n). As shown in Figure 24A, a data symbol from a first user 1 is converted to parallel symbols until the number (Nu (1)) of subcarriers allocated to the first user 1. Subcarriers allocated to individual users (n) can be equal to each other or different from each other so that the individual's data symbols can be converted to the same or different numbers of parallel symbols. In this case, the different numbers of parallel symbols are denoted by Nu (n).

Parallel data symbols for a specific user are mapped to Nu (n) subcarriers assigned to an nth user among all Nc subcarriers, and the remaining Nc- (nu (n)) subcarriers map to the data symbols of the subcarriers. other users in step S13. Through a symbol-to-subcarrier mapping module, the subcarrier in which no user is allocated is filled with "0", that is, a zero padding. The output from the symbol-to-subcarrier mapping module is converted to time domain signals by an Nc point IFFT (Inverted Fast Fourier Transform) module in step S14.

A cyclic prefix (CP) is inserted into the OFDM symbol generated by the above-mentioned IFFT module to reduce inter-symbol interference (ISI) in step S15. OFDM symbols with CP inserted are converted to serial symbols by a parallel to serial converter in step S16, and then the serial symbols are transmitted to a receiver.

Referring to Fig. 24B, the receiver data processing method according to the OFDMA scheme is performed in reverse order of a transmitter data processing method. The received data symbols pass in the S / P converter and the Nc point FFT module and then a mapping process from the subcarrier to the symbol is applied to the resulting data symbols. Parallel symbols are converted to serial symbols, unmapped, and a continuous stream of bits is generated.

The aforementioned turbo code, among a variety of channel encoding methods, will be described below.

A turbo encoder includes two encoders (that is, a constituent encoder and a recursive systematic convolution encoder) and an interleaver. The interleaver is designed to facilitate parallel decoding of the turbo code and is a type of Quadratic Polynomial Permutation (QPP). This QPP interleaver has defined the size of only one specific data block. The larger the data block size, the better the turbo code performance.

However, a real communication system divides a predetermined size block of data (for example, a transport block) into several smaller size blocks of data and then encodes smaller blocks of data. really convenient to implement the actual communication system. These smaller data blocks are called code blocks. In other words, a single code key of greater length is divided into several blocks of code. In general, a single code unit coded for both CRC and early error correction is called a code key. However, the term "code key" of the present invention indicates a data unit. This data unit is acquired when the transport block added with CRC is encoded with respect to the channel. Therefore, if the size of a single transport block is larger than a reference value and then segmented into two or more code blocks, all code blocks are coded relative to the channel so that a single key of code be made.

In general, code keys are the same size. But because of the QPP1 interleaver size limitation, one block of code among several blocks of code may have a different size. An early error correction coding process is performed on units of a code block, and interleaving is also performed on the resulting data, so that the influence of a burst error during an RF channel transmission can be reduced. .

Subsequently, the resulting data is mapped to actual radio resources and then transmitted to a destination. Since the amount of radio resources used for actual transmission is constant, speed matching for coded code blocks is required. In general, speed matching is performed by a drilling or repeating process. Speed matching can be performed in units of a coded block of code, as in the 3GPP WCDMA system. The systematic part and parity part of the coded code block are separated from each other, and the speed matching can be performed on each of them.

Fig. 25 is a conceptual diagram illustrating a method for separating a systematic part and a parity part of a coded code block from each other, and for performing a velocity matching on the separate parts.

Referring to Figure 25, a circular temporary storage can perform speed matching according to a transmission start position and the size of the data to be transmitted. In Figure 25, a code rate is assumed to be 1/3.

The spatial multiplexing-based MIMO communication system uses the SCW (Single Code Key) method and the MCW (Multiple Code Keys) method. The SCW method indicates that a single code key is transmitted through several continuous Tx data streams, and the MCW method indicates that one or more code keys are transmitted.

Figures 26A - 26B are conceptual diagrams illustrating a single code key (SCW) and multiple code keys (MCW) 1 respectively. A hybrid of the SCW and MCW methods may also be available. For example, as long as four Tx antennas and four Rx antennas are used, only two code keys can be used. In this case, two SCWs transmitting two continuous streams of data are interconnected so that the MCW system is configured.

Figure 27 shows a coding string used for an HS-DSCH of a WCDMA system according to the present invention.

If spatial multiplexing is used, a maximum of 2 continuous data streams can be transmitted, and continuous data streams are transmitted via MCWs. A coding string of a first case, in which a single continuous stream of data is transmitted, is the same as that of a second case, in which two continuous streams of data are transmitted.

If a wireless communication system transmits data via multiple Tx antennas, a data processing method for effectively segmenting a single code key into two or more layers will be described below.

In order to reduce the influence of fading on the wireless communication system, the present invention provides a data processing method for transmitting data via multiple Tx antennas, and a detailed description thereof will be given below.

Fading is one of the main reasons that cause a deterioration of wireless communication system performance. The channel gain value changes over time, frequency and space. The lower the channel gain, the worse the performance. One diversity method used as one of the solutions to the fading phenomenon uses the fact that there is a low probability that all independent channels have low gain values. In general, the greater the distance of time, frequency or space, the greater the independence of a correlation of a channel gain value between two points in time, frequency or space. Therefore, in order to solve the fading problem, the code-block-coded bits are arranged to be evenly dispersed over a temporal, frequency, or spatial domain, so that they acquire a greater gain from diversity.

The following embodiments will disclose examples in which the inventive features of the present invention are applied to a Developed Universal Mobile Telecommunication System (E-UMTS). E-UMTS can also be called a Long Term Evolution (LTE) system. The UMTS or E-UMTS technical specifications were prescribed in Communiqués 7 and 8 of the Technical Specification Group Radio Access Network of the 3rd Generation Partnership Project (GPP).

Figure 28 shows a subframe structure of the downlink Frequency Division Duplex of an LTE system according to the present invention.

Referring to Figure 28, a single subframe has a short length of 1 ms, so that the degree of channel variation on a time axis is low. But a maximum of 20 MHz can be used on a frequency geometry axis, so that channel variation on the frequency geometry axis is high. Channels can be independent of each other on a geometry axis of space so that they are evenly distributed on the geometry axes of frequency and space to gain a diversity gain. The aforementioned embodiments of the present invention may be applied not only to the FDD system, but also to a Duplex Time Division (TDD) system having a different subframe than that of the FDD system.

Figures 29A - 29B show transmission chain structures of an LTE system according to the present invention. Figure 29A is a three-layer Class 3 transmission frame and Figure 29B is a four-layer Class 4 transmission frame.

In conjunction with embodiments for effectively reducing code-to-layer key mapping combinations, the structure of Figure 29A may correspond to a third combination of Table 28, and the structure of Figure 29B may correspond to a fourth combination of Table 28.

The term "transport block" has been widely used for the UMTS or E-UMTS system, and is a basic data unit exchanged through a transport channel. A first transport block TB1 of Fig. 29A goes through a data processing step of a transmission chain so that it is connected in a single continuous data stream (i.e., a single layer). In other words, the CRC is added to a single transport block by the CRC append algorithm, and is coded relative to the channel so that the coded result relative to the channel is allocated in a single layer. The term "transport block" has been widely used for the UMTS or E-UMTS system, and is a basic data unit exchanged through a transport channel. Channel coding can be performed by a turbo code or Low Density Parity Check (LDPC) code.

In the case of a second transport block (TB2) of figure 29A and the first and second transport blocks (TB3 and TB4) of figure 29B, a single transport block is connected in two continuous streams of data (ie two layers). ). If the size of the single transport block is larger than a predetermined value, the single transport block is segmented into several code blocks (CBs). In this case, the CRC can be attached in units of a code block or transport block. Also, if required, the transport block with attached CRC is segmented into several code blocks, and the CRC can be reattached to each code block. Channel coding is performed in units of a code block. When channel-encoded code blocks are allocated at each layer, a data processing step that takes into account spatial diversity is required. The continuous streams of symbol data allocated to each layer are pre-encoded for transmission by multiple antennas so that they are transmitted to a receiver via multiple Tx antennas.

A variety of embodiments associated with the data processing step before data is allocated to each layer after channel coding of Figures 29A and 29B will be described below.

Fig. 30 shows a transmission chain structure according to one embodiment of the present invention.

Referring to Figure 30, each code block encoded with respect to channel CB1 or CB2 includes a systematic part and a parity part. A speed matching module 81 performs speed matching on coded blocks of code relative to the channel. The velocity matching process indicates that the encoded code block sizes relative to the channel are matched to a predetermined value. For example, a transmission start position is controlled by the circular temporary storage of figure 25 so that the size of a code key to be transmitted can be adjusted. Speed matching may be performed for each coded block of code relative to the channel or may also be performed in a general part in which all code blocks are interconnected.

The spatial division module 82 divides the continuous bit rate stream into two continuous bit streams, and transmits the two continuous bit streams. In this case, the order of the individual bits in the bit stream is unchanged. The number of streams of split bits is equal to the number of layers. The number of layers in figure 30 is 2.

Split bit continuous streams are applied to symbol mapping modules 83a and 83b. Each symbol mapping module 83a or 83b performs symbol mapping on received bit streams and transmits a symbol sequence. In order to perform symbol mapping, QPSK (Quadrature Phase Shift Manipulation), 16QAM (Quadrature Amplitude Modulation) or 64QAM methods can be used, but it is understood that the scope of the present invention is not limited to the above. methods, and can also be applied to other methods if necessary.

The continuous streams of output symbol data from each symbol mapping module 83a or 83b are applied to each interleaver 84a or 84b. Each interleaver 84a or 84b interleaves each continuous stream of symbols, so that the order of symbols is rearranged. It is preferable that the interleaving be set to an OFDM symbol-based interleaving. OFDM symbol-based interleaving indicates that a symbol assigned to a subcarrier is interleaved into a single OFDM symbol. The order of symbols assigned to the subcarriers is rearranged by OFDM symbol-based interleaving. The continuous streams of individual symbol data interspersed by each of the interleavers 84a and 84b are assigned to individual layers, respectively.

Fig. 31A shows a transmission chain structure according to another embodiment of the present invention.

Referring to Fig. 31A, a speed matching module 91 performs speed matching on coded code blocks with respect to channel CB1 and CB2. A symbol mapping module 92 performs symbol mapping on a bit stream generated from the velocity matching module 91 and transmits a continuous stream of symbols. Detailed descriptions of the aforementioned speed matching and the aforementioned symbol mapping are given in Figure 30, so that they will be omitted here.

An interleaver 93 receives the continuous stream of symbols from the symbol mapping module 92, performs interleaving on the received continuous stream of symbols and rearranges the order of symbols. Preferably 1 the interleaver 93 can perform the interleaving of the symbols corresponding to the code blocks CB1 and CB2 so that the symbols are uniformly mixed. In other words, a continuous stream of symbols to which a first channel-coded code block (CB1) is mapped and the other continuous stream of symbols to which a second code block (CB2) is mapped are uniform. mixed by the interleaving shown in Fig. 31A (b). Preferably, the order of symbol rearrangement by interleaving can be predetermined by a given algorithm, and OFDM symbol-based interleaving can be performed on the symbols shown in Fig. 30.

A spatial division module 94 divides a continuous stream of output symbols from interleaver 93 into several continuous streams of data according to the number of layers and transmits the continuous streams of divided data. Continuous streams of divided data are allocated to individual layers. In Fig. 31A, the interleaver 93 and the space division module 94 are physically spaced from each other, but they can be integrated into one unit as required. In other words, interleaver 93 performs interleaving and divides Rx data into several continuous symbol streams, so that the continuous streams of individual symbols can also be allocated to individual layers.

31B shows a transmission chain structure according to yet another embodiment of the present invention.

Referring to FIG. 31B, a stream of data bits is matched to the speed by a rate matching module 95, and the matched rate bitstream is applied to a bit-level interleaver 96. The interleaver at bit level 96 performs bit stream interleaving of the Rx data. Preferably the interleaving may be performed in units of a bit group equipped with at least one bit. The number of bits contained in each bit group is equal to the number of bits mapped to a single symbol in each symbol mapping module 98a or 98b. For example, if the BPSK scheme is used as the symbol mapping method in the first or second symbol mapping modules 98a or 98b, each bit group includes a single bit. If the QPSK schema is used as the symbol mapping method, each bit group includes two bits. If the 16QAM scheme is used as the symbol mapping method, each bit group includes 4 bits. Figure 31B shows the case in which the QPSK scheme is used as the symbol mapping method. The continuous stream of data bits written in a row direction by the bit-level interleaver 96 is read in the direction of a column based on a bit group consisting of two bits and then transmitted.

The continuous stream of data bits generated from bit-level interleaver 96 is divided into several units according to the number of layers by the spatial division module 97. The first and second symbol mapping modules 98a and 98b are performed. do symbol mapping on the continuous streams of data bits divided by the spatial division module 97. Figure 31B shows the case where QPSK is used as the symbol mapping method so that two bits are mapped to a single symbol. In Figure 31B, the spatial division order caused by the spatial division module 97 and the symbol mapping caused by the first and second symbol mapping modules 98a and 98b can be changed to another order. In other words, symbol mapping is first performed on the continuous stream of data generated from the bit-level interleaver 96 and then the continuous streams of symbols are segmented according to the number of layers.

The continuous flows of individual symbols generated from the first and second symbol mapping modules 98a and 98b of Fig. 31B are the same as those of the spatial division module 94 of Fig. 31A.

An OFDM (OS) Symbol-based interleaver 93 of Fig. 31A performs symbol-level interleaving, and a bit-level interleaver 96 of Fig. 31B performs bit-level interleaving. However, bit-level interleaver 96 performs interleaving in units of a bit group consisting of bits corresponding to the symbol mapping method, so that bit-level interleaving has the equivalent result to that of interleaving. at symbol level. And while the spatial division module 97 of Fig. 31B is located after a single symbol mapping module, as shown in Fig. 31A, the same equivalent effect is made.

Fig. 32A shows a transmission chain structure according to yet another embodiment of the present invention.

Although the structure of Fig. 32A is similar to that of Fig. 31A, it is understood that the spatial division module 94 of Fig. 31A is replaced by the spatial distribution module 104. The spatial distribution module 104 divides the continuous streams of symbols. generated by the interleaver 103 according to the number of layers and at the same time rearranges the order of the symbols. Namely, in Figure 32A (b), the order of symbols corresponding to the individual code blocks is rearranged according to a given interleaving algorithm by interleaver 103, and is divided into several continuous symbol streams by the spatial distribution module. 104, so that the order of the symbols is readjusted by a predetermined scheme. In this case, the spatial distribution module 104 is considered to perform spatial interleaving. For example, a single symbol stream is configured by symbols in an even ordinal position between all continuous symbol streams corresponding to individual code blocks, and the other symbol stream can be configured by symbols in an odd ordinal position. . The method for readjusting the order of symbols by the spatial distribution module 104 can be freely determined within the scope of maximizing the spatial diversity effect. In Fig. 32A, in the case of a real system implementation, interleaver 103 and spatial distribution module 104 may be integrated into one unit as required. Detailed descriptions of speed matching module 101, symbol mapping module 102, and interleaver 103 are the same as those in Fig. 31.

Figure 32B shows a transmission chain structure according to yet another embodiment of the present invention.

Compared to Fig. 32A, the embodiment of Fig. 32B controls a bit-level interleaver 106 to perform interleaving based on a bit group consisting of at least one bit, according to the symbol mapping method used for the first few. and second symbol mapping modules 108a and 108b, in the same manner as the embodiment of Fig. 31b. If streams of data bits that depend on the number of layers are spatially distributed by spatial distribution module 107, streams of data bits must be distributed based on a bit group used for bit-level interleaver 106. In the case of a real implementation, bit-level interleaver 106 and spatial distribution module 107 may be integrated with each other as required.

In Fig. 32B, the spatial distribution order caused by the spatial distribution module 107 and the symbol mapping caused by the first and second symbol mapping modules 108a and 108b may change to another order. In other words, although the spatial distribution module 107 of Fig. 32B is located after a single symbol mapping module, as shown in Fig. 32A, the same equivalent effect is made.

Fig. 33 shows a transmission chain structure according to another embodiment of the present invention.

Compared to Fig. 32A, the order of a spatial distribution module 113 and interleavers 114a and 114b in the embodiment of Fig. 33 is opposite to that of Fig. 32A. In other words, the continuous symbol stream generated from the symbol mapping module 112 is divided into two continuous symbol streams by the spatial distribution module 113. In this case, the spatial distribution module 113 readjusts the order of symbols. - such that the continuous streams of divided symbols include uniformly symbols corresponding to the code blocks CB1 and CB2 and at the same time divides the continuous streams of symbols generated from symbol mapping module 112. Each interleaver 114a or 114b interleaves the continuous symbol stream generated from the spatial distribution module 113 so that the symbols are rearranged.

The continuous symbol streams generated from the individual interleavers 114a and 114b are allocated in individual layers. In the structure of Fig. 33, the spatial distribution module 113 and the interleavers 114a and 114b can be integrated with each other in a real implementation process.

The embodiments of FIGS. 30 and 33 can also perform bit-based interleaving of coded code blocks with respect to the channel prior to performing the symbol mapping process. In other words, the embodiments of FIGS. 30 and 33 perform bit group-based interleaving of the coded code blocks with respect to the channel prior to performing the symbol mapping process, so that the order of the bits contained in the code blocks can be rearranged.

OS-based interleaving may not be used in the aforementioned modes of figures 30 and 33. In this case, if the case in which two code blocks are contained in a single symbol is not allowed, processing based on symbol is easier than bit-based processing. For example, if it is assumed that speed-matched CB1 is 10-bit long and CB2 is 10-bit long, and CB1 and CB2 use 16QAM, a single symbol is set at 4-bit intervals. , so that the last 2 bits of CB1 and the first 2 bits of CB2 are contained in a single 16QAM symbol. If the above consideration is not allowed, the length of CB1 or CB2 should be restricted to the multiple of an integer of a modulation order. This case is the same as the other case in which OS-based merge is used as an identity merge. Therefore, although OS-based interleaving is not used, the symbol mapping module and spatial division (or distribution) module proposed by the present invention can also be used without any change.

The foregoing descriptions have disclosed the method for reducing the number of code-key stream (or code-key data) mapping combinations, the layer-mapping process, and the method for effectively transmitting data. The foregoing embodiments may be readily understood and modified by those skilled in the art in various ways in accordance with the above principles. For example, the layer mapping method of Fig. 29A or 29B may be performed by the key code - streaming data combinations shown in Table 28 so that input data can be encoded relative to the channel, modulated accordingly. with a symbol mapping scheme, and be mapped to each layer (or each continuous stream of data). Figures 29A and 29B correspond to the third and fourth combinations shown in Table 28 as previously stated.

If a single code key is mapped to two layers according to the third and fourth combinations of Table 28, individual modulation symbols can alternatively be mapped to two layers by the spatial distribution module 113 of Fig. 33. shown in Fig. 33, a symbol in the even ordinal position is mapped to a first layer 1 and a symbol in the odd ordinal position is mapped to a second layer 2 so that a diversity gain is acquired. Needless to say, the order of the symbol at the even ordinal position and the symbol at the odd ordinal position may change to another order as needed.

The above functions may be performed by a microprocessor, controller, microcontroller or Application Specific Integrated Circuit (ASIC) based on software data or program codes. The design, development and implementation of the above codes can easily be implemented by those skilled in the art.

It will be appreciated that most of the terminology disclosed in the present invention is defined by consideration of the functions of the present invention, and may be differently determined according to the intent of those skilled in the art or usual practice. It is therefore preferable that the above terminology be understood on the basis of all contents disclosed in the present invention.

It will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention as long as they fall within the scope of the appended claims and their equivalents.

Industrial Applicability

As is apparent from the foregoing description, although the aforementioned embodiments have been disclosed based on 3GPP LTE1 the scope of the present invention is not limited to this 3GPP LTE and may also be applied to other wireless communication systems with based on MIMO.

The method for indicating a combination of a code key and a continuous data stream according to one embodiment of the present invention may rationally limit the number of all combinations between a code key and a continuous data stream. consideration for a variety of aspects, so that it can reduce the number of bits of information indicating the number of all combinations of a code key and a continuous stream of data. As for the above aspects, the above method considers a maximum baud rate of a specific code key, compares usability with the number of cases that indicates a matching combination, keeps a combination available for retransmission, improves performance decoding a receiver using the Successive Noise Canceling (SIC) method 1 and consider a streaming data array based on an antenna array and consider the convenience of a user in a multiuser MIMO communication system.

Therefore, the present invention indicates all key code - streaming data combinations that are required for both an uplink and a downlink in a lower bit number MIMO communication system, thereby increasing efficiency. of control information.

The present invention provides a method for mapping the system, transmitting the mapped code blocks and additionally ensuring a spatial diversity gain caused by spatial multiplexing.

In the event that a single data block is divided into several code blocks and the code blocks are coded with respect to the channel, the present invention gives each code block sufficient spatial diversity by adding simple functions to a channel. chain of transmission.

While preferred embodiments of the present invention have been disclosed for illustration purposes, those skilled in the art realize that various modifications, additions and substitutions are possible without departing from the scope or spirit of the invention as disclosed in the appended claims.

Claims (16)

1. Layer mapping method for spatial multiplexing in a Multigrade and Multisided (MIMO) system, Characterized by the fact that the layer mapping method comprises: a) modulating a predetermined bit block from each of the at least one code key and generate a continuous stream of modulation symbols for each code key; and (b) map the modulation symbol for each of the at least one code key to at least one layer according to a specific combination of predetermined mapping combinations, wherein in each of the predefined mapping combinations. determined, the number of layers to which a single code key is mapped is limited to or below a predetermined number, the predetermined number corresponding to an acquired ratio when the number of all layers is divided by number of all code keys. Layer mapping method according to claim 1, characterized in that: the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys; and the predetermined mapping combination limits the number of layers to which the single code key is mapped to 2 or less. A layer mapping method according to claim 1, characterized in that, in the predetermined mapping combination, a combination in which a single code key is mapped to at least two layers when one is used. maximum of one code key, is removed between all available mapping combinations between at least one code key and at least one layer. A layer mapping method according to claim 1, characterized in that, in the predetermined mapping combination, a combination in which a single code key is mapped to at least two layers when the maximum number of all for 2 layers, is removed between all available mapping combinations between at least one code key and at least one layer. Layer mapping method according to claim 1, characterized in that the predetermined mapping combination is limited to a combination in which a lower index code key is mapped to A single layer and the other code key with a higher index are mapped to two layers when two code keys are mapped to three layers. Layer mapping method according to claim 1, characterized in that the predetermined mapping combination is adjusted such that combinations with the same number of code keys and layers are denoted by a single combination. A layer mapping method according to claim 1, characterized in that: the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination consists of in a first combination in which a single code key is mapped to a single layer, a second combination in which two code keys are mapped to two layers respectively, a third combination in which two code keys are mapped to three layers, and a fourth combination in which two code keys map up to four layers. A layer mapping method according to claim 1, characterized in that: the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination consists of in a first combination in which a single code key is mapped to a single layer, a second combination in which two code keys are mapped to two layers, respectively, a third combination in which two code keys are mapped to three layers; and a fourth combination in which two code keys are mapped to up to four layers, and a fifth combination to support relaying based on a Hybrid ARQ (HARQ) scheme. A layer mapping method according to claim 7 or 8, characterized in that, in the third combination, a first code key between the two code keys is mapped to a first layer between the three layers and one. The second code key between the two code keys is mapped to the second and third layers between the three layers. A layer mapping method according to claim 7 or 8, characterized in that, in the fourth combination, a first code key between the two code keys is mapped to the first and second layers between the four layers. , and a second code key between the two code keys is mapped to the third and fourth layers between the four layers. Layer mapping method according to claim 7 or 8, characterized in that: in layer mapping step b), if a specific code key is mapped to two layers according to the third or fourth In combinations between the predetermined mapping combinations, the modulation symbols that build on a specific code key are alternatively mapped to both layers. 12. Method for a Transmitter of a Multitrack and Multitransmitter (MIMO) system to transmit data via multiple transmit antennas (Tx), characterized in that the method comprises: a) performing a channel coding on a specific data block ; b) modulating a bit block formed by the coded data block with respect to the channel and generating a continuous stream of modulation symbols; c) mapping modulation symbols contained in any of the predetermined mapping combinations; and d) transmitting the mapped symbols relative to the layer, wherein each of the predetermined mapping combinations includes a specific combination in which a single code key constituted by the continuous stream of symbols generated by said specific data block modulation is mapped. up to at least two layers, and the specific combination is designed to alternatively map the continuous streams of symbols that build the single code key to at least two layers. A method according to claim 12, characterized in that: the MIMO system uses a maximum of 4 layers and a maximum of 2 code keys, and the predetermined mapping combination includes a first combination in the where a single code key is mapped to a single layer, a second combination in which two code keys are mapped to two layers, respectively, a third combination in which two code keys are mapped to three layers, and a fourth combination in the which two code keys map up to four layers. A method according to claim 13, characterized in that, in the third combination, a first code key between the two code keys is mapped to a first layer between the three layers, and a second code key. say between the two code keys is mapped to the second and third layers between the three layers. A method according to claim 13, characterized in that, in the fourth combination, a first code key between the two code keys is mapped to the first and second layers between the four layers, and a second code key. code between the two code keys is mapped to the third and fourth layers between the four layers. A method according to claims 14 or 15, characterized in that: in layer mapping step c), if a specific code key is mapped to two layers according to the third or fourth combinations between In the predetermined mapping combinations, an index symbol at the even ordinal position between the continuous streams of symbols building on a specific code key is mapped to a first layer between the two layers, and an index symbol at the odd ordinal position. it is mapped to a second layer between the two layers, so that the index symbol at the even ordinal position and the index symbol at the odd ordinal position are alternatively mapped to the first and second layers.