KR20060070901A - Apparatus for transmitting and receiving to provide a space diversity gain in ultra-wideband multi-band ofdm system - Google Patents

Abstract

The present invention relates to a transceiver for providing a spatial diversity gain in a UWB MB-OFDM system. The present invention relates to the diversity gain provided by the MB-OFDM system proposed as one of the IEEE 802.15 TG3a standards for UWB applications. The present invention relates to a diversity gain in the frequency domain due to center frequency hopping and a time domain diversity gain due to redundant transmission of time domain OFDM symbols. The present invention proposes a time and frequency domain diversity gain provided by the existing MB-OFDM system, and employs blocks of transmitters and receivers of the SFBC MB-OFDM system in which SFBC, which is a representative spatial diversity scheme, is applied to the MB-OFDM system. And provide additional spatial diversity gain to the MB-OFDM system.

UWB, MB-OFDM, Space Diversity, Gain

Description

TECHNICAL FIELD The transceiver for providing spatial diversity gain in an MW-OPDM system.             

1 is a conventional Diagram of frequency band of MB-OFDM system.

2 is a diagram of the structure of a conventional MB-OFDM UWB modem.

3 is a diagram for physical layer parameters of an MB-OFDM system.

4 is a diagram of a PLCP preamble of an MB-OFDM system.

5 is a time-frequency code diagram of an MB-OFDM system.

6 is a diagram of a transmission rate of an MB-OFDM system.

7 is a diagram for a UWB channel model.

8 is a diagram of frequency hopping diversity gain of an MB-OFDM system.

9 is a diagram of time-domain diversity gain of an MB-OFDM system.

10 is a diagram of a transmitter structure of an SFBC MB-OFDM system according to the present invention;

11 is a diagram of a receiver structure of an SFBC MB-OFDM system according to the present invention;

12 is a diagram of a spatial diversity gain of an SFBC MB-OFDM system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1001: Scrambler 1002: Convolutional Encoder

1003: Puncturer 1004: Bit Interleaving Block

1005: Time / Frequency Spreading Block 1006: SFBC Encoder

1007, 1010: Insert Pilot & VC IFFT Add CP & GI Blocks

1008, 1011: DA converter (DAC)

1009, 1012: Time-Frequency Code Generator

1101: bandpass filter (BPF) 1102: low noise amplifier (LNA)

1103: time-frequency domain code generator 1104: baseband filter (LPF)

1105: VGA 1106: ADC

1107: AGC 1108: Synchronization Remove CP FFT

1109: Carrier Phase and Time Tracking

1110: Space Frequency Decoder 1111: Channel Estimator

1112: Time-Frequency Despreading 1113: Deinterleaver

1114: De-Puncturer 1115: Viterbi Decoder

1116: Descrambler

The present invention relates to a transceiver for providing spatial diversity gain in a UWB MB-OFDM system, and more particularly, to a diversity gain provided by an MB-OFDM system proposed as one of the IEEE 802.15 TG3a standards for UWB applications. Spatial Diversity in UWB MB-OFDM System Improves System Performance by Gaining Diversity Gain in Frequency Domain by Center Frequency Hopping and Time Domain Diversity Gain by Overlapping Transmission of Time-domain OFDM Symbols The present invention relates to a transceiver for providing a gain.

In general, UWB (Ultra-Wideband) is a military technology used by the US Department of Defense over the last 40 years, providing hundreds of Mbps of transmission speed under a wireless PAN (WPAN) environment, but the power consumption of conventional mobile phones or WLANs. It has the advantage of only one tenth of the power consumption. Nevertheless, commercial use has been banned due to interference problems with communication systems using other existing bands that can be caused by using very wide frequency bands. However, in February 2002, the Federal Communications Commission (FCC) was allowed to commercialize, subject to frequency band limitations ranging from 3.1 GHz to 10.6 GHz and emission limits below -41.25 dBm per MHz. Accordingly, IEEE 802.15 TG 3a has been actively standardized recently to define Alternate PHY for high speed WPAN with UWB-based physical layer while utilizing existing IEEE 802.15.3 MAC. MB-OFDM, proposed by the Multi-Band OFDM Alliance (MBOA), in which companies participate, is considered as a strong standardization candidate.

Since MB-OFDM system is basically an OFDM-based system, it can effectively remove ISI (Inter-symbol Interference) for multipath delay, and it is based on Bluetooth and WLAN using unlicensed band of 2.4GHz / 5GHz. There is an advantage that can easily cope with the interference.

FIG. 1 is a diagram of a frequency band of an MB-OFDM system. The MB-OFDM system includes four groups of three bands covering the entire 7.5 GHz band from 3.1 GHz to 10.6 GHz, limited by the FCC for indoor wireless communication. It is divided into (Group A, B, C, D) and one group consisting of two bands (Group E). Currently, Mode 1, which uses only Group A from 3.1 GHz to 4.8 GHz, is selected as Mandatory. In Mode 1, interference between the diversity effect and the SOP (Simultaneous Operating Piconet) in the frequency domain can be minimized by using a Time Frequency Interleaved (TFI) structure in which an OFDM signal is frequency hoped over three bands.

2 shows the structure of a baseband modem of a conventional MB-OFDM system. Data of the transmitting end of the MB-OFDM system passes through the scrambler 211, the convolutional encoder 212, and the puncturer 213, and converts the data into a symbol having a desired coding rate, and then passes through the bit interleaver 214 and the modulator 215. It forms the frequency domain signal of MB-OFDM system. After the pilot data is added to the frequency domain signal, an Inverse Fast Fourier Transform (IFFT) and a guard interval are inserted to form a time domain OFDM signal of the IFFT Insert Pilots Add Prefix / GI block 216. The DAC 217 then converts the digital signal into an analog signal, and then hops the center frequency by the time frequency domain code provided by the time-frequency domain code generator 218. send.

The signal entering the receiver of the MB-OFDM system is passed through a passband filter (BPF) 221 and a low noise amplifier (LNA) 222 and then provided by a time-frequency domain code generator (223). After a suitable center frequency is found by using a time frequency domain code, the analog signal is converted to digital through a baseband filter (LPF) 224 and an ADC 226. The VGA 225 and AGC 227 blocks correct power signal attenuation differences due to channel frequency differences. Synchronization / Release Perform frequency and time synchronization, remove Guard Time, and fast fourier via Cyclic Prefix / FFT Block (228) and Carrier Freq & Time Tracking Block (230). Transform) transforms the time domain signal into the frequency domain. The original signal is recovered through the descrambling process of the channel estimator 229, the de-interleaver 231, the depuncturer 232, the Viterbi decoder 233, and the de-scrambler 234. do.

Accordingly, the MB-OFDM UWB system provides time domain diversity by repeatedly transmitting the same OFDM symbol, and also provides diversity in frequency domain because the center frequency is hopped every symbol. However, there is a problem that the MB-OFDM UWB system does not yet provide the diversity gain of the spatial domain.

The present invention has been proposed to solve the problems of the prior art, and an object of the present invention is for the diversity gain provided by the MB-OFDM system proposed as one of the IEEE 802.15 TG3a standards for UWB applications. In order to improve the performance of the system by obtaining additional diversity gain in addition to the diversity gain in the frequency domain due to hopping and the time domain diversity gain due to redundant transmission of time domain OFDM symbols, the time and time provided by the existing MB-OFDM system By presenting the frequency-domain diversity gain and suggesting the transmitter and receiver block diagrams of the SFBC MB-OFDM system using SFBC, which is a representative spatial diversity scheme, the MB-OFDM system provides additional spatial diversity gain. Transceiver with Spatial Diversity Gain in UWB MB-OFDM Systems To provide.

In order to achieve the object of the present invention, the present invention is a representative spatial diversity scheme for the 2 x 1 antenna structure in order to obtain a spatial diversity gain in addition to the time and frequency domain diversity provided by the existing MB-OFDM UWB system In order to apply the SFBC scheme to the MB-OFDM system, a transmitter of the SFBC MB-OFDM system using a spatial diversity scheme, and a receiver of the SFBC MB-OFDM system using the spatial diversity scheme are configured. Provided is a transceiver for providing spatial diversity gain in a UWB MB-OFDM system.

In addition, the transmitter of the SFBC MB-OFDM system using the spatial diversity scheme of the apparatus for utilizing spatial diversity in the UWB MB-OFDM system according to the present invention may obtain a spatial diversity gain at the transmitting end of the SFBC MB-OFDM system. And inserting the SFBC encoding block into the transmitting end of the existing MB-OFDM system and transmitting the data from the SFBC encoding block through the two antennas.

In addition, a receiver of an SFBC MB-OFDM system using the spatial diversity scheme inserts an SFBC decoding block into a receiver of an existing MB-OFDM system to decode SFBC encoded data at a receiver of the SFBC MB-OFDM system. Obtaining the diversity gain.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are merely to illustrate the present invention is not limited to the contents of the present invention.

The present invention describes a method of improving the performance of the system by showing the diversity gain basically provided by the MB-OFDM system and the spatial diversity gain obtained by applying the SFBC technique to the existing MB-OFDM system.

The physical layer specification of the basic MB-OFDM system is shown in FIG. Of the 128 subcarriers, 100 subcarriers are data subcarriers for transmitting information, and 12 subcarriers are used as pilot subcarriers distributed evenly over the entire frequency for synchronization. It is used as a protection and virtual carrier available for various other purposes.

4 shows a PLCP preamble used for initial synchronization and channel estimation of an MB-OFDM system. The preamble consists of 21 packet sequence OFDM symbols consisting of a packet synchronization sequence, three frame synchronization sequence OFDM symbols consisting of a frame synchronization sequence, and six channel estimation sequence OFDM symbols consisting of a channel estimation sequence. All the symbols constituting the frame of the MB-OFDM system are to reduce the interference with SOPs and to improve the system performance by applying the frequency diversity scheme, the time-frequency of the MB-OFDM system of FIG. Referring to the drawing of the code, the channel 1 is allocated to {1 2 3 1 2 3} and the channel 2 is assigned to {1 3 2 1 3 2} as shown in the Time-Frequency Code (TFC) Changes are made.

The MB-OFDM system uses only QPSK modulation, but can support various transmission rates of 53.3, 55, 80, 106.7, 110, 160, 200, 320, 400, and 480 Mbps through coding rate and frequency / time domain spreading. -Specifications for each data rate in the OFDM system are summarized in FIG. The frequency domain spreading technique places a modulated symbol on each subcarrier by complex symmetry based on the DC subcarrier. This approach reduces the hardware of the RF stage by one-half because it consists of only real signals in the time domain. In addition, the time-domain spreading technique transmits one OFDM symbol twice in the time domain. Since the repeated two symbols are transmitted through different frequency bands, it is possible to obtain diversity gain in the time domain and diversity gain in the frequency domain. do. The scrambler is composed of PBS (Pseudo Random Binary Sequence) with ^15th generation polynomial 1+ x ¹⁴ + x ^{15. The} initial register value can be selected from four given values, and the receiver receives 2-bit information for setting the initial value. Is sent. The channel encoder removes the bits encoded according to the puncturing pattern based on the convolutional encoder having the constraint length of K = 7 (133 ₈ , 156 ₈ , 175 ₈ ) and code rate 1/3, so that 11/32, 1 / Code rates of 2, 5/8, and 3/4 can be obtained. The interleaver of MB-OFDM is composed of two levels of bit block interleaver. Firstly, symbol interleaving is block interleaving between OFDM symbols, and attempts to use frequency diversity from each subband, and blocks interleaving with six symbols. Tone interleaving, which is performed second, interleaves adjacent bits constituting one OFDM symbol to be transmitted to different subchannels, and blocks interleaving by collecting coded bits to be transmitted in one OFDM symbol.

The UWB channel model is configured to develop a channel model suitable for the UWB environment. The SG3a subcommittee was finally proposed in February 2003 to analyze the physical layer performance of 802.15 TG3a. The SG3a UWB channel model is given in four types, CM1 to CM4, as shown in FIG. 7, of which CM1, CM2, and CM3 are modeled based on actual measured parameters, and CM4 is the worst case with RMS delay of 25ns. Yi considered a poor situation. According to this channel model, each of 100 implementation channels is given. Since the UWB channel model is a 6 GHz wideband channel model, in order to apply to the MB-OFDM system, the existing UWB channel must be filtered and reshaped into three subband channels in consideration of the frequency band and the center frequency hopping of the MB-OFDM system. do.

The MB-OFDM system provides the diversity gain of the time domain because the same OFDM symbol is transmitted twice, and also the frequency gain of the frequency domain when each symbol is transmitted.

FIG. 8 is a performance curve showing diversity gain due to frequency hopping provided by the MB-OFDM system. In the UWB channel model CM3, a Practical channel estimation is performed using a preamble symbol provided by the MB-OFDM system and MRC Combining is applied. If the frequency hopping is not performed, the simulation results are for 110Mbps. When frequency hopping is not performed, the diversity effect due to frequency hopping cannot be obtained, and only noise averaging effect can be obtained, indicating that performance is degraded by about 4 dB at 10 ^-4 BER than when frequency hopping is considered.

9 is a performance curve showing the time-domain diversity gain provided by the MB-OFDM system. In case of 110 Mbps data rate in CM3 under the assumption of perfect channel estimation, the MRC scheme is applied to two symbols provided by the time-domain spreading scheme. This is the BER performance curve for the case and simple mean after channel estimation. Applying MRC, we can see that there is a performance improvement of about 15dB at 10 ^-4 BER rather than taking a simple average.

The existing MB-OFDM system provides frequency domain diversity gain due to frequency hopping and time domain diversity gain due to repetitive transmission of OFDM symbols in the time domain, but does not provide diversity of spatial domain. Accordingly, the present invention provides a method for providing spatial domain diversity in addition to time and frequency domain diversity by applying SFBC, which is a representative spatial diversity scheme, to an existing MB-OFDM system.

10 shows a block diagram of a transmitting end of an SFBC MB-OFDM system using a spatial diversity scheme. The data of the transmitting end of the SFBC MB-OFDM system is passed through a scrambler 1001 block. The scrambler 1001 inputs a bit stream and an input generated by a 15 th order polynomial (1 + x ¹⁴ + x ¹⁵ ). Export the value of the exclusive OR of the data to the output. The data passing through the scrambler enters the input of the convolutional encoder 1002 and becomes output data having a coding rate of 1/3. This data is input to the input of the puncturer 1003. If a suitable puncturing pattern is applied to the input data and subjected to a puncturing process, data having a desired coding rate can be obtained. The data passing through the puncturer passes through the bit interleaver 1004. The bit interleaver 1004 applies the interleaving process between six OFDM symbols and interleaving within one symbol and outputs the data to the output. This data passes through a Time / Frequency Spreading Block 1005, where the same data is repeated in the frequency domain and time domain of the OFDM symbol. Diversity gain can be obtained.

Data passing through the Time / Frequency Spreading Block 1005 is SFBC encoded via an SFBC encoder 1006, so that the frequency domain signals X1 [n] and X2 [n for two transmit antennas. Is converted to].

Insert Pilots & VC, IFFT, and Add CP & GI blocks 1007 and 1010 respectively add pilot data and virtual carriers to the frequency domain signals X1 [n] and X2 [n] to be transmitted through the antenna. After the Inverse Fast Fourier Transform process, a guard interval is inserted to form a time domain OFDM signal.

The time domain OFDM signal passes through the DACs 1008 and 1011. Through this process, the OFDM signal in the digital domain is converted into the OFDM signal in the analog domain.

The converted analog OFDM signal is carried on an RF carrier having a center frequency determined by time-frequency code blocks 1009 and 1012.

The difference from the conventional MB-OFDM is that the two antennas are used on the transmitter side and that the SFBC encoder 1006 has a time / frequency spreading block 1005 in order to obtain a spatial signal processing gain. It's placed behind the scenes.

11 shows a receiver block diagram of an SFBC MB-OFDM system. The receiving end of the SFBC MB-OFDM system extracts an RF signal of a desired band through a band pass filter (BPF) 1101. The signal is amplified via a Low Noise Amplifier (LNA) 1102 to minimize the effects of noise. The RF signal passed through the low noise amplifier (LNA) 1102 is down-converted using the center frequency determined by the time frequency domain code generator 1103 to convert the frequency into a baseband signal. Since the baseband signal also includes unnecessary signals generated during the downconversion process, the baseband filter (LPF) 1104 is passed to obtain a desired baseband signal, and then the analog OFDM signal is converted into a digital OFDM signal through the ADC 1106. Convert to

Due to the frequency hopping characteristic of the MB-OFDM system, data may be transmitted through different center frequency carriers. In this case, the AGC (Automatic Gain Control) block 1107 is different because power difference of the signal due to the difference in center frequency is different. Determine how much power compensation should be done and send it to the input of the variable gain amplifier (VGA) block 1105.This value is used to change the VGA to the output value of the amplifier so that even if there is a difference in the center frequency carrier, Power attenuation corrects the signal to recover.

The synchronization / removal CP / FFF block 1108 removes Guard Time from the time-domain OFDM signal and performs an FFT to convert the time-domain signal into the frequency domain. At this time, the frequency and time synchronization process of the Carrier Phase and Time Tracking block 1109 is performed in parallel.

The transmitter decodes the SFBC-encoded data through a space frequency decoder block 1110 which provides an SFBC decoder function. In this process, the channel estimate value of the channel estimator 1111 is decoded. I use it. The signal passing through the SFBC decoder despreads the signal spread in the time and frequency domains through a time / frequency despreading block 1112. In addition, the interleaved data is aligned in the original order through the deinterleaver 1113 block. Then, the data is restored to 1/3 coding rate through the Depuncturer (1114) block, decoded convolutionally encoded data through the Viterbi decoder (1115) block, and the 15th generation polynomial used by the transmitting end of the MB-OFDM system. The original signal is recovered through a descrambling process (1116) of exclusively ORing the bit stream generated by 1 + x ¹⁴ + x ¹⁵ ) and the Viterbi decoded data.

The difference from the existing MB-OFDM system is that there is a space frequency decoder 1110 for recovering SFBC encoding.

Figure 12 is a perfect channel estimation on the assumption that (Perfect Channel Estimation), the BER performance curves of the basic MB-OFDM system with SFBC MB-OFDM system supporting a data rate of 110Mbps in the CM3, 10 than the conventional MB-OFDM ^system It can be seen that the performance improvement is about 1.5 dB at ⁴ BER.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below Or it may be modified.

As described above, the transceiver for providing the spatial diversity gain in the UWB MB-OFDM system according to the present invention is not only the time and frequency domain diversity provided by the existing MB-OFDM system but also the spatial diversity by the antenna. It can also be used to operate the system at lower power, and can be applied to short-range wireless communication such as a home network.

In addition, Ultra-Wideband (UWB) systems can provide significantly higher throughput than IEEE 802.11 (Wireless LAN) or Bluetooth, and many predict the rapid growth of the UWB market in many applications, such as local area networks. It is attracting attention as an attractive new wireless communication system from operators and companies. Therefore, the present invention for the SFBC MB-OFDM system showing the same performance with less power is good in terms of marketability.

In addition, the UWB system is expected to replace the IEEE 802.11a / b series WLAN in the commercialization market in the next two to three years. SFBC MB-OFDM system can guarantee the same transmission rate with low power, so many companies are expected to be interested and there is a possibility of industrialization.

Claims (7)

In order to obtain the spatial diversity gain in addition to the time and frequency domain diversity provided by the existing MB-OFDM UWB system, the SFBC scheme, which is a representative spatial diversity scheme, is applied to the MB-OFDM system for a 2 x 1 antenna structure. Transmitter of an SFBC MB-OFDM system using a spatial diversity technique; And And a receiver of an SFBC MB-OFDM system using the spatial diversity scheme. The method of claim 1, The transmitter of the SFBC MB-OFDM system using the spatial diversity scheme Inserting the SFBC encoding block into the transmitting end of the existing MB-OFDM system and transmitting the data from the SFBC encoding block through the two antennas in order to obtain a spatial diversity gain in the transmitting end of the SFBC MB-OFDM system; Transceiving apparatus for providing a spatial diversity gain in the UWB MB-OFDM system, characterized in that. The method of claim 1, The receiver of the SFBC MB-OFDM system using the spatial diversity scheme And inserting the SFBC decoding block into the receiver of the existing MB-OFDM system to obtain spatial diversity gain in order to decode the SFBC encoded data at the receiver of the SFBC MB-OFDM system. A transceiver for providing spatial diversity gain in an OFDM system. The method of claim 1, The transmitter of the SFBC MB-OFDM system using the spatial diversity scheme A scrambler 1001 that receives data from a transmitting end of an SFBC MB-OFDM system and outputs a value obtained by exclusively ORing a bit stream generated by a ^15th generation polynomial (1 + x ¹⁴ + x ¹⁵ ) and input data; A convolutional encoder (1002) which receives data output from the scrambler (1001) and provides output data having a coding rate of 1/3; A puncturer 1003 for obtaining data of a desired coding rate when the output data of the convolutional encoder 1002 is received and subjected to a puncturing process by applying a puncturing pattern to the input data; A bit interleaver (1004) outputted by applying the data passed through the puncturer (1003) by applying interleaving between six OFDM symbols and interleaving within one symbol; Receiving the output data of the bit interleaver 1004, the same data is repeated in the frequency domain and time domain of the OFDM symbol, so that the time / frequency spreading block 1005 for obtaining the diversity gain of the frequency domain and time domain Including, An SFBC encoder 1006 which receives the data passed through the time / frequency spreading block 1005 and is subjected to SFBC encoding and converted into frequency domain signals X1 [n] and X2 [n] for two transmitting antennas; After the pilot data and the virtual carrier are added to the frequency domain signals X1 [n] and X2 [n] to be transmitted through the antennas, the IFFT process is performed. Insert Pilots & VC, IFFT, Add CP & GI blocks 1007 and 1010 forming an OFDM signal; DACs 1008 and 1011 receiving the time-domain OFDM signal and converting an OFDM signal in a digital domain into an OFDM signal in an analog domain; Time-frequency domain code generators 1009 and 1012 for determining the center frequency of the RF carrier for transmitting the converted analog OFDM signal; And Transmitting and receiving device for providing a spatial diversity gain in the UWB MB-OFDM system, characterized in that it comprises a transmitting antenna (ANT1, ANT2) for transmitting the converted analog OFDM signal to the RF carrier having the predetermined center frequency . The method of claim 1, The SFBC encoder 1006 is disposed behind a time / frequency spreading block 1005 to obtain a spatial signal processing gain, and if there is a difference from the existing MB-OFDM system, the SFBC encoder 1006 And a transmitter for providing a spatial diversity gain in a UWB MB-OFDM system, characterized by using the two transmit antennas. The method of claim 1, The receiver of the SFBC MB-OFDM system using the spatial diversity scheme A band pass filter (BPF) 1101 for filtering a signal received through the reception antenna into a predetermined frequency band to extract an RF signal of a desired band; A low noise amplifier (LNA) 1102 that amplifies an RF signal of a desired band emitted from the bandpass filter (BPF) 1101 while minimizing the influence of noise; A time frequency domain code generator (1103) for determining an RF carrier center frequency required for the downconversion of the RF signal through the low noise amplifier (LNA) 1102 to a baseband signal; A baseband filter (LPF) 1104 for outputting a desired baseband signal by performing low pass filtering because the baseband signal includes unnecessary signals generated during downconversion; Due to the frequency hopping characteristics of the MB-OFDM system, data can be transmitted through different center frequency carriers.In this case, the power attenuation of the myths due to the center frequency difference is different. A variable gain amplifier (VGA) 1105 and an automatic gain controller (AGC) 1107 block for correcting the signal to be restored; An ADC 1106 for converting an analog OFDM signal into a digital OFDM signal; A sync / removal CP / FFF block 1108 which removes Guard Time from the time domain OFDM signal and converts the time domain signal to the frequency domain by performing FFT; In the sync / removal CP / FFF block 1108, a guard time is removed from a time domain OFDM signal, and a carrier phase for performing a frequency and time synchronization process in parallel when performing a FFT to convert a time domain signal into a frequency domain and Time Tracking block 1109; The signal passing through the SFBC decoder includes a time / frequency despreading block 1112 for despreading a signal read in the time and frequency domain; A deinterleaver 1113 block for fitting the interleaved data in the original order; A Depuncturer 1114 block for reconstructing data with a coding rate of 1/3; A Viterbi decoder 1115 block for decoding convolutionally encoded data; The original signal is restored and output through the descrambling process of exclusively ORing the bit stream generated by the 15th generation polynomial (1 + x ^ 14 + x ^ 15) and the Viterbi decoded data used by the transmitter of the MB-OFDM system. Includes a descrambler 1116, A space frequency decoder block 1110 for providing an SFBC decoder function to the SFBC-encoded data provided by the transmitting / removing CP / FFF block 1108; And And a channel estimator (1111) using a channel estimate value in the SFBC decoding process in the spatial frequency decoder block. The method of claim 1, The space frequency decoder (1110) is a transmission and reception device for providing a space diversity gain in the UWB MB-OFDM system, characterized in that existing to restore the SFBC encoding, unlike the existing MB-OFDM system.

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