KR100843251B1 - Apparatus and method for transmitting signal with multiple antennas - Google Patents

Abstract

Disclosed are a transmission apparatus having multiple antennas and a signal transmission method using multiple antennas.

The multi-antenna transmission apparatus receives a signal for transmission, performs space-time encoding or frequency-space encoding, generates a plurality of delayed signals by cyclically delaying the encoded signals through a plurality of delay values, and spatially delays the delayed signals. Each area and delay value are transmitted to the channel through different antennas.

By adjusting the number of delay values for the cyclic delay, the number of antennas of the transmitting apparatus can be flexibly expanded.

Alamouti, Cylic delay diversity (CCD), Cylic shift diversity (CSD), Space-frequency block code (SFBC), Space-time block code (STBC)

Description

Apparatus and method for transmitting signal using multiple antennas {APPARATUS AND METHOD FOR TRANSMITTING SIGNAL WITH MULTIPLE ANTENNAS}

1 is a diagram illustrating a signal transmission apparatus according to a first embodiment of the present invention.

2 is a diagram illustrating a cyclically delayed signal according to an embodiment of the present invention.

3 is a diagram illustrating a signal transmission apparatus according to a second embodiment of the present invention.

4 is a flowchart illustrating a signal transmission method according to an embodiment of the present invention.

5 is a flowchart illustrating a signal transmission method according to another embodiment of the present invention.

6 is a graph illustrating the performance of transmitting a code rate of 2/3 in a flat fading channel environment according to an embodiment of the present invention.

7 is a graph illustrating the performance of transmitting a code rate of 2/3 in a low speed selective fading channel environment according to an embodiment of the present invention.

8 is a graph illustrating the performance of transmitting a code rate of 2/3 in a fast selective fading channel environment according to an embodiment of the present invention.

The present invention relates to a signal transmission apparatus and method. In particular, the present invention relates to a signal transmission apparatus and method having low reception complexity and flexibility in increasing the number of antennas.

The main performance measures for designing signal transmission devices in a multi-antenna communication system are diversity gain and reception complexity. Various multi-antenna transmission schemes have been proposed to obtain the maximum diversity gain, one of which is the Alamouti transmission scheme.

According to the Alamouti transmission method, the signal transmission apparatus includes two transmission antennas and has 1 as a transmission rate. Alamouti transmission methods are widely used because they have the maximum diversity gain and low reception complexity. However, when the signal transmission apparatus uses three or more transmission antennas, it does not have a transmission rate of 1 for maximum diversity gain and low reception complexity. On the other hand, in order to obtain a transmission rate of 1 and maximum diversity gain, there is a problem in that reception complexity becomes very large.

In order to solve this problem, in case of four transmitting antennas, two independent Alamouti transmission blocks are used as shown in Equation 1 ('IEEE802.16e / D12, Part 16: Air interface for fixed and mobile broadband wireless access'). systems', Oct. 2005, p.473-474).

In the matrix shown in Equation 1, each row represents a signal transmitted to different transmit antennas, the first and third columns represent signals transmitted at time k, and the second and fourth columns represent signals transmitted at time k + 1. . Alamouti transport blocks composed of the first and second columns and Alamouti transport blocks composed of the third and fourth columns are transmitted using different orthogonal resources (different subcarriers in the case of orthogonal frequency division multiplexing).

However, the transmission method as shown in Equation 1 is a method in which a loss of diversity gain is taken for low reception complexity and a transmission rate of 1. It is also not suitable for transmission devices that still use three or five transmit antennas.

It is an object of the present invention to provide a signal transmission apparatus and method having low reception complexity and good reception quality and having flexibility in increasing the number of antennas.

A transmitting device according to an embodiment of the present invention includes a space-time encoder, a plurality of cyclic delay groups, and a plurality of antenna groups. The space-time encoder receives a signal and encodes the plurality of spatial domains and one or more time domains, and outputs a plurality of encoded signals for each of the plurality of spatial domains according to the time domain. A plurality of cyclic delay groups respectively correspond to the plurality of spatial regions, and a plurality of delay signals are generated by cyclically delaying the corresponding coded signals through a plurality of delay values. The plurality of antenna groups respectively correspond to the plurality of cyclic delay groups, and include a plurality of antennas for transmitting the plurality of delay signals from the corresponding cyclic delay group to the channel, respectively.

A transmission apparatus according to another embodiment of the present invention includes a frequency space encoder, a plurality of cyclic delay groups, and a plurality of antenna groups. The frequency space encoder receives a signal and performs encoding on a plurality of spatial domains and one or more frequency domains, and outputs a plurality of encoded signals for each of the plurality of spatial domains according to the frequency domain. A plurality of cyclic delay groups respectively correspond to the plurality of spatial regions, and a plurality of delay signals are generated by cyclically delaying the corresponding coded signals through a plurality of delay values. The plurality of antenna groups respectively correspond to the plurality of cyclic delay groups, and include a plurality of antennas for transmitting the plurality of delay signals from the corresponding cyclic delay group to the channel, respectively.

A transmission method according to an embodiment of the present invention comprises the steps of: receiving a signal and performing encoding on a plurality of spatial domains and at least one time domain to output a plurality of encoded signals for each of the plurality of spatial domains according to the time domain; And generating a plurality of delay signals by cyclically delaying each of the encoded signals through a plurality of delay values, and transmitting the plurality of delay signals to channels through different antennas, respectively.

According to another embodiment of the present invention, a method of transmitting a signal includes receiving a signal and performing encoding on a plurality of spatial domains and one or more frequency domains to output a plurality of encoded signals for each of the plurality of spatial domains according to the frequency domain And generating a plurality of delay signals by cyclically delaying the coded signals through a plurality of delay values, and transmitting the plurality of delay signals to channels through different antennas, respectively.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a diagram illustrating a signal transmission apparatus 100 according to a first embodiment of the present invention.

As shown in FIG. 1, the apparatus 100 for transmitting a signal according to the first embodiment of the present invention includes a space-time encoder 110, G cyclic delay groups 120, G guard interval insertion groups 130, and G antenna groups 140 are included.

The space-time encoder 110 receives the signal s (n) and encodes the G space domains and the m time domains to generate G * m encoded signals. Here, the spatial domain is a term for describing an encoding operation of the space-time encoder 110. As will be described later, one spatial region does not correspond to one antenna but corresponds to an antenna group composed of a plurality of antennas. The space-time encoder 110 outputs an encoded signal for each of the G space regions according to the time domain between 1 and m. That is, the space-time encoder 110 outputs G coded signals for each unit time domain. The space-time encoder 110 may be an Alamouti encoder or a V-BLAST encoder, but is not limited thereto.

Next, the space-time encoder 110 will be described in detail with an Alamouti encoder, a space-time transmit diversity encoder, and a V-BLAST encoder as an example.

If the space-time encoder 110 is an Alamouti encoder, the following equation (2) is used.

That is, the Alamouti coder receives two signals s (2k) and s (2k + 1) to generate four coded signals by performing space-time encoding on two spatial domains and two temporal domains. In the matrix of Equation 2, the signal of each row means a signal transmitted to different spatial regions, and the signal of each column means a signal transmitted to different time domains.

According to Equation 2, the Alamouti encoder outputs a signal s (2k) for the first spatial domain and a signal s (2k + 1) for the second spatial domain at time 2k. The Alamouti encoder outputs a signal -s ^* (2k + 1) for the first spatial domain and a signal s ^* (2k) for the second spatial domain at time 2k + 1.

When the space-time encoder 110 is a space-time transmission diversity encoder, the following equation 3 is used.

According to Equation 3, the space-time transmission diversity encoder receives two signals s (2k) and s (2k + 1) to perform space-time encoding on two spatial domains and two time domains, thereby encoding four encodings. Generate a signal. The space-time transmit diversity encoder then outputs a signal s (2k) for the first space region at time 2k and a signal -s ^* (2k + 1) for the second space region. The space-time transmit diversity encoder then outputs signal s (2k + 1) for the first spatial region and time signal s ^* (2k) for the second spatial region at time 2k + 1.

If the space-time encoder 110 is a V-BLAST encoder, the following equation (4) is used.

That is, the V-BLAST encoder generates two encoded signals by receiving two signals s (2k) and s (2k + 1) and performing space-time encoding on two spatial domains and one temporal domain. In the matrix of Equation 4, the signal of each row means a signal transmitted to different spatial regions.

According to Equation 4, the V-BLAST encoder outputs signal s (2k) for the first spatial region at time k and outputs signal s (2k + 1) for the second spatial region.

The signal transmission apparatus 100 includes G cyclic delay groups 120. The G cyclic delay groups 120 correspond to the G spatial regions used when the space-time encoder 110 performs encoding. The cyclic delay group 120 receives the coded signals X _g , g = 1, 2, ... G from the space-time encoder 110 and outputs a plurality of delay values τ _{[g, 0]} = 0, τ _{[g A} plurality of delay signals (Y _{[g, 0]} , Y _{[g, 1]} , ...), which are cyclically delayed through _{, 1]} , τ _{[g, 2]} , ...), respectively. The retarder 121 of the.

The signal transmission apparatus 100 includes G guard interval insertion groups 130. The G guard interval insertion groups 130 correspond to the G cyclic delay groups 120, respectively. The guard interval insertion group 130 protects against inter-symbol interference on the plurality of delay signals Y _{[g, 0]} , Y _{[g, 1]} , ... from the corresponding cyclic delay group 120. Cyclic Prefix (CP) inserters for inserting intervals (Cyclic Prefixes for OFDM), respectively, to generate a plurality of guard interval insertion symbols Z _{[g, 0]} , Z _{[g, 1]} , ... 131).

A delay signal generated by the cyclic delay group 120 and a guard interval insertion symbol generated by the guard interval insertion group 130 will be described with reference to FIG. 2.

2 is a diagram illustrating a symbol in which a cyclically delayed signal and a guard interval are inserted according to an embodiment of the present invention.

FIG. 2 illustrates a delay signal and a guard interval insertion symbol generated centering on a coded signal X ₁ corresponding to a first space region among the outputs of the space-time encoder 110.

The space-time encoder 110 generates an encoded signal X _{1 and} provides the encoded signal X ₁ to the cyclic delay group 120. The coded signal X ₁ is a symbol of symbol period T that has not yet been delayed.

If the cyclic delay group 120 delays the coded signal X ₁ through three delay values 0, T / 4, and T / 2, the cyclic delay group 120 generates a delay signal Y _{[1, 0]} ), delay signal Y _[1,1] , delay signal Y _[1,2] . That is, the same as the delay signal (Y _[1,0]) is the input signal is a coded signal (X ₁₎ of the encoded signal (X ₁₎ a cyclic group delay (120), so the delayed signal cyclically through the delay 0 It is a signal. Since the delay signal Y _[1,1] is a signal in which the coded signal X ₁ is cyclically delayed through the delay value T / 4, the signal corresponding to the last T / 4 of the coded signal X ₁ is a coded signal ( X ₁ ) is the signal shifted before, and the delay signal Y _[1,2] is a signal in which the coded signal X ₁ is cyclically delayed through the delay value T / 2, and thus the last T of the coded signal X ₁ . The signal corresponding to / 2 is the signal moved in front of the coded signal X ₁ .

The symbols Z _[1,0] , the symbols Z _[1,1] , and the symbols Z _[1,2] , which are guard interval insertion symbols, are delay signals Y _[1,0] and delay signals Y. _[1,1] ) and a delay signal Y _[1,0] are symbols in which a cyclic prefix Cyclic Prefix is inserted. For example, the guard interval insertion symbol (Z _[1,0]) is the symbol insert the last part of the signal interval of the delay signal (Y _[1,0]) before the delayed signal (Y _[1,0]).

Referring back to FIG. 1, the apparatus 100 for transmitting a signal includes G antenna groups 140, and the G antenna groups 140 correspond to the G guard period insertion groups 130, respectively. The antenna group 140 includes an antenna 141 corresponding to the number of CP inserters 131 of the corresponding guard period insertion group 130. One antenna 141 corresponds to one CP inserter 131, and transmits a guard interval insertion symbol, which is an output of the corresponding CP inserter 131, to the channel. Referring to FIG. 2 by way of example, when the antenna group 140 includes a first antenna, a second antenna, and a third antenna, the first antenna may include a guard interval insertion symbol Z _[1,0] and a second antenna. The antenna transmits the guard interval insertion symbol Z _[1,1] and the third antenna transmits the guard interval insertion symbol Z _[1,2] on the channel.

When the signal transmission apparatus 100 does not include the guard interval insertion group 130, the G antenna groups 140 correspond to the G cyclic delay groups 120, respectively, and the cyclic delay group 120. It includes an antenna 141 corresponding to the number of the delay value or the number of the delay unit 121 of the cyclic delay group 120. N _g (g = 1, 2, ..., G) delay signals from the cyclic delay group 120 are transmitted to the channel through the N _g antennas included in the antenna group 140.

3 is a diagram illustrating a signal transmission apparatus 200 according to a second embodiment of the present invention.

As shown in FIG. 3, the apparatus 200 for transmitting a signal according to the second embodiment of the present invention includes a frequency space encoder 210, G cyclic delay groups 220, G guard interval insertion groups 230, And G antenna groups 240.

The frequency space encoder 210 receives the signal s (n) and encodes the G space domain and the m frequency domain to generate G * m encoded signals. The frequency space encoder 210 outputs an encoded signal for each of the G space regions by varying the frequency domain between 1 and m. That is, the frequency space encoder 210 outputs G coded signals for each unit frequency domain. The frequency-space encoder 210 may be an Alamouti encoder or a V-BLAST encoder, and the present invention is not limited thereto. Details thereof may be easily derived from the description of the frequency-space encoder 210 and thus will be omitted.

The signal transmission apparatus 200 includes G cyclic delay groups 220, and each of the G cyclic delay groups 220 is included in each of the G spatial regions used when the frequency space encoder 210 performs encoding. Corresponds. The cyclic delay group 220 receives the coded signals X _g , g = 1, 2, ... G from the frequency-space coder 210 with a plurality of delay values τ _{[g, 0]} = 0, τ _{[ A} plurality of delay signals Y _{[g, 0]} , Y _{[g, 1]} , ... are generated by circularly delaying through _{g, 1]} , τ _{[g, 2]} , ...), respectively. .

The signal transmission device 200 includes G guard interval insertion groups 230. The G guard interval insertion groups 230 correspond to the G cyclic delay groups 220, respectively. The guard interval insertion group 230 protects the intersymbol interference on the plurality of delay signals Y _{[g, 0]} , Y _{[g, 1]} , ... from the corresponding cyclic delay group 220. And a plurality of CP inserters 231 for inserting intervals to generate a plurality of guard interval insertion symbols Z _{[g, 0]} , Z _{[g, 1]} , ..., respectively. Signal transmitting apparatus 200 ) Includes G antenna groups 240, and each of the G antenna groups 240 corresponds to the G guard interval insertion groups 230. The antenna group 240 includes an antenna 241 corresponding to the number of CP inserters 231 of the corresponding guard period insertion group 230. One antenna 241 corresponds to one CP inserter 131 and transmits a guard interval insertion symbol that is an output of the corresponding CP inserter 231 to the channel.

Next, a signal transmission method according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 is a flowchart illustrating a signal transmission method according to an embodiment of the present invention.

First, the space-time encoder 110 receives a signal for transmission and encodes a plurality of (G in FIG. 1) spatial domains and one or more temporal domains, thereby encoding a plurality of encoded signals for a plurality of spatial domains according to the temporal domain. (X ₁ to X _G in Figure 1) is output (S110).

Next, the cyclic delay group 120 includes a plurality of delay values (N _g (g = 1, ..., G) in FIG. 1) (0, τ _{[g, 1]} , τ _{[g, 2]} , ...), a plurality of delay signals (N _g in FIG. 1) of delay signals (Y _{[g, 0]} , FIG. Y _{[g, 1]} , Y _{[g, 2]} , ...) are generated (S120).

The guard interval insertion group 130 then includes a plurality of (N _g in FIG. 1) delay signals (Y _{[g, 0]} , Y _{[g, 1]} , Y in FIG. 1) from the cyclic delay group 120. _{[g, 2],} ...) the input received guard interval insertion symbol (Z in Figure 1 _{[g, 0]} of N pieces _g) in a plurality (Fig. 1 by inserting a guard interval (CP) for each delayed signal, Z _{[g, 1]} , Z _{[g, 2]} , ...) is generated (S130).

Thereafter, the signal transmission apparatus 100 transmits a plurality of guard interval insertion symbols generated by the guard interval insertion group 130 to channels through different antennas (S140). In this case, when the signal transmission apparatus 100 does not include the guard interval insertion group 130, the signal transmission apparatus 100 may channel a plurality of delay signals generated by the cyclic delay group 120 through different antennas. To transmit.

5 is a flowchart illustrating a signal transmission method according to another embodiment of the present invention.

First, the frequency space encoder 210 receives a signal for transmission and encodes a plurality of G domains and one or more frequency domains to encode a plurality of spatial domains according to the frequency domains. A signal (X ₁ to X _G in FIG. 3) is output (S210).

Next, the cyclic delay group 220 includes a plurality of delay values (N _g (g = 1, 2, ..., G) in FIG. 3) (0, τ _{[g, 1]} , τ _[ in FIG. 3). _{g, 2]} , ..., and cyclically delay the coded signals, which are output signals of the frequency-space coder 210, respectively, to thereby output a plurality of delay signals (Y _{[g, 0]} , Y _{[g, 1} in FIG. 3). _] , Y _{[g, 2]} , ...) is generated (S220).

The guard interval insertion group 230 then comprises a plurality of (N _g in FIG. 3) delay signals (Y _{[g, 0]} , Y _{[g, 1]} , Y in FIG. 3) from the cyclic delay group 220. _{[g, 2],} ...) the input received guard interval insertion symbol (Z in Fig. 3 _{[g, 0]} of N pieces _g) in a plurality (Fig. 3 by inserting a guard interval (CP) for each delayed signal, Z _{[g, 1]} , Z _{[g, 2]} , ...) are generated (S230).

Then, the signal transmission apparatus 200 includes a plurality of guard interval insertion symbols generated by the guard interval insertion group 230 (Z _{[g, 0]} , Z _{[g, 1]} , Z _{[g, 2]} in FIG. 3 _). , ...) are transmitted to channels through different antennas (S240). In this case, when the signal transmission apparatus 200 does not include the guard interval insertion group 230, the signal transmission apparatus 200 may transmit a plurality of delay signals generated by the cyclic delay group 220 through different antennas. Send to the channel.

Next, the performance of the present invention will be described with reference to FIGS. 6 to 8.

FIG. 6 is a graph illustrating performance when a signal having a code rate of 2/3 is transmitted to four transmitting antennas in a flat fading channel environment according to an embodiment of the present invention. Is a graph illustrating the performance measured in a slow selective fading channel (Pedestrian A channel) environment according to an embodiment of the present invention, Figure 8 is a highly selective fading channel (highly selective) according to an embodiment of the present invention It is a graph showing the performance measured in the fading channel (TU channel) environment.

6 to 8, graphs 11, 21, and 31 of pure cyclic shift diversity (CSD) show four signals generated by circularly delaying one signal through four delay values according to the cyclic delay diversity technique. It shows the performance of a multi-antenna transmitter for transmitting delay signals to four antennas, respectively. In addition, the graphs 12, 22, and 32 of pure space-time block codes (STBC) of the multi-antenna transmission apparatus each transmitting four signals generated for four spatial regions according to Equation 1 to four antennas, respectively. Performance. Finally, the graphs 13, 23, 33 of Combined STBC / CSD transmit four signals to four antennas, each of which is generated by cyclically delaying two output signals of the Alamouti encoder through two delay values. It shows the performance of the multi-antenna transmission apparatus according to the embodiment of the present invention.

Referring to FIG. 6, the multi-antenna transmission apparatus according to the embodiment of the present invention is the same as the multi-antenna transmission apparatus using the Pure CSD method or the Pure STBC method when transmitting a signal having a code rate of 2/3 in a flat fading channel environment. It can be seen that the SNR has a low block error rate.

In addition, referring to FIG. 7, the multi-antenna transmission apparatus according to the embodiment of the present invention has a lower error rate at the same SNR than the multi-antenna transmission apparatus using the Pure CSD method or the Pure STBC method in a low-speed selective fading channel environment. Can be.

Referring to FIG. 8, the multi-antenna transmission apparatus according to the embodiment of the present invention has similar performance as the multi-antenna transmission apparatus using the Pure STBC method in a fast selective fading channel environment, but the multi-antenna transmission using the Pure CSD method. It can be seen that it has better performance than the device.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, the number of antennas of a transmitting apparatus can be flexibly extended by adjusting the number of spatial regions for encoding and the number of delay values for cyclic delay.

In addition, the multi-antenna transmission apparatus according to the present invention has a good quality (low error rate) compared to the multi-antenna transmission apparatus using the Pure CSD method or the Pure STBC method.

Claims (15)

A transmitting device for transmitting a signal to a channel, A space-time encoder configured to receive a first signal and perform encoding on a plurality of spatial domains and one or more time domains, and output a plurality of encoded signals for each of the plurality of spatial domains according to the one or more time domains; A plurality of cyclic delay groups corresponding to the plurality of spatial regions, respectively, for generating a plurality of delay signals by cyclically delaying the corresponding coded signals through a plurality of delay values; And And a plurality of antenna groups each corresponding to the plurality of cyclic delay groups, the plurality of antenna groups including a plurality of antennas for transmitting the plurality of delay signals from the corresponding cyclic delay group to the channel, respectively. The method of claim 1, A plurality of guard interval insertion groups respectively corresponding to the plurality of cyclic delay groups and generating guard interval insertion symbols by inserting guard intervals into the plurality of delay signals from the corresponding cyclic delay groups, respectively; Including, The plurality of antenna groups respectively correspond to the plurality of guard interval insertion groups, and includes a plurality of antennas for transmitting the plurality of guard interval insertion symbols from the corresponding guard interval insertion group to the channel, respectively. The method of claim 1, And the space-time encoder receives the first signal and performs Alamouti encoding on two space domains and two time domains. The method of claim 1, The space-time encoder receives the first signal and performs space-time transmit diversity coding on two space domains and two time domains. The method of claim 1, And the space-time encoder receives the first signal and performs V-BLAST encoding on two spatial domains and one temporal domain. The method according to any one of claims 1 to 5, One of the plurality of delay values of the circular delay group is zero. The method according to any one of claims 1 to 5, The cyclic delay group generates two delay signals by cyclically delaying the coded signals through two delay values. In a method for transmitting a signal to a channel, Receiving a first signal and performing encoding on a plurality of spatial domains and one or more time domains, and outputting a plurality of encoded signals for each of the plurality of spatial domains according to the one or more time domains; Generating a plurality of delay signals by cyclically delaying each of the plurality of encoded signals through a plurality of delay values; And And transmitting the plurality of delay signals to the channel through different antennas, respectively. The method of claim 8, Generating a plurality of guard interval insertion symbols by inserting guard intervals into the plurality of delay signals, respectively; The step of transmitting to the channel And transmitting the plurality of guard interval insertion symbols to the channel through different antennas. A transmitting device for transmitting a signal to a channel, A frequency space encoder receiving a first signal and performing encoding on a plurality of spatial domains and one or more frequency domains and outputting a plurality of encoded signals for each of the plurality of spatial domains according to the one or more frequency domains; A plurality of cyclic delay groups corresponding to the plurality of spatial regions, respectively, for generating a plurality of delay signals by cyclically delaying the corresponding coded signals through a plurality of delay values; And And a plurality of antenna groups each corresponding to the plurality of cyclic delay groups, the plurality of antenna groups including a plurality of antennas for transmitting the plurality of delay signals from the corresponding cyclic delay group to the channel, respectively. The method of claim 10, A plurality of guard interval insertion groups respectively corresponding to the plurality of cyclic delay groups and generating guard interval insertion symbols by inserting guard intervals into the plurality of delay signals from the corresponding cyclic delay groups, respectively; Including, The plurality of antenna groups respectively correspond to the plurality of guard interval insertion groups, and includes a plurality of antennas for transmitting the plurality of guard interval insertion symbols from the corresponding guard interval insertion group to the channel, respectively. The method of claim 10, And the frequency space encoder receives the first signal and performs Alamouti encoding on two spatial domains and two frequency domains. The method according to any one of claims 10 to 12, The cyclic delay group generates two delay signals by cyclically delaying the coded signals through two delay values. In a method for transmitting a signal to a channel, Receiving a first signal and performing encoding on a plurality of spatial domains and one or more frequency domains and outputting a plurality of encoded signals for each of the plurality of spatial domains according to the one or more frequency domains; Generating a plurality of delay signals by cyclically delaying each of the plurality of encoded signals through a plurality of delay values; And And transmitting the plurality of delay signals to the channel through different antennas, respectively. The method of claim 14, Generating a plurality of guard interval insertion symbols by inserting guard intervals into the plurality of delay signals, respectively; The step of transmitting to the channel And transmitting the plurality of guard interval insertion symbols to the channel through different antennas.

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