USRE43059E1 - Wireless communication system and method using grouping maximum likelihood detection - Google Patents
Wireless communication system and method using grouping maximum likelihood detection Download PDFInfo
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- USRE43059E1 USRE43059E1 US12/759,974 US75997410A USRE43059E US RE43059 E1 USRE43059 E1 US RE43059E1 US 75997410 A US75997410 A US 75997410A US RE43059 E USRE43059 E US RE43059E
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B1/707—Spread spectrum techniques using direct sequence modulation
- H04B1/7097—Interference-related aspects
- H04B1/711—Interference-related aspects the interference being multi-path interference
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/02—Channels characterised by the type of signal
- H04L5/023—Multiplexing of multicarrier modulation signals
- H04L5/026—Multiplexing of multicarrier modulation signals using code division
Definitions
- the present invention relates to a system and method for reducing the effects of multi-path fading and signal interference in a system using orthogonal codes and binary signal values. More specifically, the present invention relates to a maximum likelihood detection (MLD) system and method that reduces the complexity of MLD and improves performance in the system using orthogonal codes and binary signal values.
- MLD maximum likelihood detection
- the modulation/demodulation methods for supporting a data transfer rate increasing in a confined frequency band include the quadrature amplitude modulation (QAM) method.
- the QAM modulation method may enhance the data transfer rate because the amount of information increases with an increase in the constellation, but it has a problem in regard to its mobility and application for 16-QAM or greater with a separation of more than a predetermined value. Namely, the QAM method is susceptible to the effect of distortion because the redundancy of noise decreases with an increase in the constellation. That is, the QAM modulation method has a trade-off relationship between information and noise.
- a wireless communication system that includes: a transmitter including an orthogonal encoder for converting serially input binary signals to parallel binary signals and orthogonally encoding the parallel binary signals, a first multiplier for multiplying the orthogonally encoded binary signals by an intrinsic spreading code to spread the orthogonally encoded binary signals, and an OFDM (Orthogonal Frequency Division Multiplexing) modulator for OFDM-modulating the spread signals; and a receiver including an OFDM demodulator for demodulating the OFDM-modulated signals, and a maximum likelihood detector for performing a maximum likelihood detection of the demodulated spread signals.
- a transmitter including an orthogonal encoder for converting serially input binary signals to parallel binary signals and orthogonally encoding the parallel binary signals, a first multiplier for multiplying the orthogonally encoded binary signals by an intrinsic spreading code to spread the orthogonally encoded binary signals, and an OFDM (Orthogonal Frequency Division Multiplexing) modulator for OFDM-modulating the spread signals; and a receiver including an OFDM demodul
- the maximum likelihood detector groups the OFDM-demodulated signals into a predetermined number of blocks to perform the maximum likelihood detection, and uses the grouped maximum likelihood detection values to perform a whole maximum likelihood detection.
- the transmitter of the wireless communication system further includes: a first serial-to-parallel converter for serial-to-parallel converting the signals spread with the intrinsic spreading code; and an interleaver for interleaving the serial-to-parallel converted signals and sending the interleaved signals to the OFDM modulator.
- the receiver further includes: a deinterleaver for deinterleaving the OFDM-demodulated signals; and a first parallel-to-serial converter for parallel-to-serial converting the deinterleaved signals and sending the parallel-to-serial converted signals to the maximum likelihood detector.
- the maximum likelihood detector includes: a second multiplier for multiplying the OFDM-demodulated signals by the intrinsic spreading code; a grouping section for grouping the multiplied signals into blocks; a grouping maximum approximation detector for performing a maximum likelihood detection of the grouped blocks; an integrated maximum approximation detector for performing a whole maximum likelihood detection based on the grouped maximum approximation values; an orthogonal despreader for orthogonally despreading a sequence having a maximum approximation value to output parallel signals; and a second parallel-to-serial converter for converting the parallel output signals to serial signals.
- FIG. 1 is a block diagram of a wireless communication system according to an embodiment of the present invention
- FIG. 2 is a detailed block diagram of a grouping maximum likelihood detector according to an embodiment of the present invention.
- FIG. 3 is a signal diagram showing the multiplication of orthogonal codes and intrinsic spreading codes.
- FIG. 1 is a block diagram of a wireless communication system according to the embodiment of the present invention.
- the wireless communication system comprises a transmitter that includes a single orthogonal code (hereinafter referred to as “TOC”) block 100 including a serial-to-parallel converter 101 , and an orthogonalizer using first to fourth orthogonal codes (hereinafter expressed as “Sub-w(1,2,3,4)”), a serial-to-parallel converter 110 , an interleaver 120 , and an OFDM modulator 130 ; and a receiver that includes an OFDM demodulator 200 , a deinterleaver 210 , a parallel-to-serial converter 220 , and a grouping maximum likelihood detector 230 .
- the configuration shown in the TOC block corresponds to the basic structure of the prior art for increasing channel capacity using orthogonal codes and binary signals.
- the TOC block 100 orthogonalizes serially input binary signals using the first to fourth Sub-w(1,2,3,4).
- the orthogonalized binary signals are summated, multiplied by an intrinsic spreading code W 1 , and sent to the serial-to-parallel converter 110 .
- the parallel bit streams output from the serial-to-parallel converter 110 are interleaved from the interleaver 120 .
- the interleaved bit streams are fed into the OFDM modulator 130 for OFDM modulation.
- the modulated signals are sent through OFDM channels.
- the individual signal waveforms of the OFDM channels are present at a point where the power of the channels of a different channel center frequency approaches zero, so they cause no interference even when they are overlapped.
- the OFDM modulated signals transferred on a plurality of carriers through the OFDM channels are demodulated from the OFDM demodulator 200 .
- the demodulated signals are deinterleaved from the deinterleaver 21 , converted to serial bit streams via the parallel-to-serial converter 220 , and sent to the grouping maximum likelihood detector 230 .
- the grouping maximum likelihood detector 230 performs MLD in the manner of the method that will be described later according to the embodiment of the present invention.
- Input data are sent to the TOC block 100 using orthogonal codes to increase channel capacity, and to the serial-to-parallel converter 110 through an intrinsic spreading code.
- the orthogonal codes, the intrinsic spreading code and the binary signal data can be used in the following description, where the binary signal data 0 and 1 are respectively denoted as “ ⁇ ” and “+” in the orthogonal codes and the intrinsic spreading code.
- W 1 (0 1 0 1 0 1 0 1) is expressed by ( ⁇ + ⁇ + ⁇ + ⁇ +).
- the spread code values are the output values before the serial-to-parallel converter 110 .
- the serial-to-parallel converted signals are fed into the interleaver 120 , and the output of the interleaver 120 through the spread data SD is transferred via the OFDM modulator 130 .
- the OFDM modulator 130 generally comprises an IFFT (Inverse Fast Fourier Transform) section, a parallel-to-serial converter, a guard interval inserter, and a carrier (RF) section, none of which are shown.
- the input binary spread code value SC can be output through the internal processing of the OFDM modulator 130 .
- the data received through the OFDM channels are fed into the deinterleaver 210 via the OFDM demodulator 200 .
- the OFDM demodulator 200 generally includes the functions of multiplying the noise-mixed input signals by the carrier (RF), removing an RF component via a low-pass filter (LPF), performing an A/D conversion, removing the guard interval, and performing an FFT, which functions are not shown.
- the deinterleaver 210 performs the reverse process of the interleaver of the transmitter and outputs the deinterleaved data to the parallel-to-serial converter 230 . After the parallel-to-serial conversion, the signal values are output as optimized values through a grouping MLD.
- the spread data SD ( ⁇ 2 +2 ⁇ 2 +2 +2 ⁇ 2 ⁇ 2 +2) are multiplied by the intrinsic spreading code W 1 through a multiplier.
- the individual values of the spread data are multiplied by the intrinsic spreading code W 1 to output a value of (+2 +2 +2 +2 ⁇ 2 ⁇ 2 +2 +2).
- the output value is revised through the grouping MLD and then fed into an orthogonal despreader 234 .
- the data fed into the orthogonal despreader 234 are multiplied by the first to fourth orthogonal codes Sub-w(1) to (4) to give the following values: (+2+2+2+2 ⁇ 2 ⁇ 2+2+2) ( ⁇ 2 ⁇ 2+2+2 ⁇ 2 ⁇ 2 ⁇ 2) (+2+2+2+2+2+2 ⁇ 2 ⁇ 2) (+2+2 ⁇ 2 ⁇ 2+2+2+2+2)
- the individual values are integrated for one period and multiplied by the value of one period (e.g., one period of W 1 is 8) to give (1, ⁇ 1, 1, 1), which is then multiplied by d.
- the restored values (d, ⁇ d, d, d) are parallel-to-serial converted into the original values.
- FIG. 2 is a block diagram of the grouping maximum likelihood detector.
- the grouping maximum likelihood detector comprises, as shown in FIG. 2 , a multiplier for multiplying an input signal by the intrinsic spreading code W 1 , a grouping maximum approximation detection processor 232 , an integrated maximum approximation detection processor 233 , a deorthogonal spreader 234 , and a parallel-to-serial converter 235 .
- the input signals from the OFDM demodulator 200 , the deinterleaver 210 , and the parallel-to-serial converter 220 are fed into the grouping maximum approximation detection processor 232 .
- the input signals are multiplied by the intrinsic spreading code W 1 and then grouped by a grouping section 231 .
- the individual bit interval information of the first to fourth orthogonal codes Sub-w(1) to (4) are summated and then multiplied by the intrinsic spreading code W 1 .
- the multiplication value is then divided by the bit interval of Sub-w(1,2,3,4) to determine the interval of the intrinsic spreading code.
- the interval of the intrinsic spreading code is 8 and the Sub-w(1,2,3,4) is a 4-bit interval, each group after grouping has an interval of 2.
- the received signals R k1 , R k2 , . . . , R kl-1 and R kl are subjected to noise and Rayleigh fading.
- the grouping maximum approximation detection processor 233 performs MLD for R kl .
- the transmitted sequence is selected that minimizes the Euclidean distance e j 2 among all the available transmitted and received sequences.
- the maximum likelihood value processed from the integrated maximum approximation processor 233 is used to perform the optimized MLD for integrated R kl blocks.
- the conventional MLD algorithm which uses the fading constant matrix H kl , requires channel information for assigning a weight to all the transmitted sequences V jl , so its complexity increases at a ratio of geometrical progression with an increase in the length of the sequence and a decrease in the Euclidean distance.
- the embodiment of the present invention groups all the user signals from the transmitter into blocks in the units of bit of the orthogonal code Sub-w(1,2,3,4) multiplied by the spreading code W 1 allocated to the users.
- 2 Nw/Sw available sequences are detected from the MLD rather than k sequences, where Nw is the interval length of the intrinsic spreading code W 1 ; and Sw is the bit interval length of each orthogonal code.
- Nw the length of the intrinsic spreading code
- Nw the length of the intrinsic spreading code
- the code length of each Sub-w(1,2,3,4) be Sw
- the transmitted signals are grouped into Sw blocks.
- the partially spread block in each unit bit has the maximum approximations of 2 Nw/Sw partially spread code bits for each partially spread code bit.
- the data bits d il each of which is spread by the orthogonal codes Sub-w(1,2,3,4), are spread by 2 Nw/Sw partially spread code vectors.
- the codes used for spreading are orthogonal Walsh-Hadamard codes and have the cross-correlation of zero.
- For the spread chip stream of the k-th block Sk having a length of Nw/Sw can be expressed by the following equation:
- the orthogonal despreader 235 uses the Sub-w(1,2,3,4) codes to despread the received signals spread with the Sub-w(1,2,3,4) codes and subjected to the grouping MLD process, and divides the resulting value of the despreading by the length of the intrinsic spreading code, Nw to obtain data values received from the transmitter.
- the data values are processed at the parallel-to-serial converter 235 into finally received data.
- FIG. 3 shows an example of the multiplication of the orthogonal code by the intrinsic spreading code.
- the lengths of the intrinsic spreading code W 1 and the orthogonal code are set to 8 and 4, respectively.
- the intrinsic spreading code has a considerably large length.
- signal 3 A shows the 2-fold expanded bit interval of one code of Sub-w(1,2,3,4)
- signal 3 B is the intrinsic spreading code W 1
- signal 3 C shows the multiplication of the intrinsic spreading code and the Sub-w(1,2,3,4), where Nw is 8, Sw is 4, and Nw/Sw is 2.
- the bit interval length of Sub-w(1,2,3,4) is 4, so the length of the intrinsic spreading code Nw is grouped into 4 blocks. Namely, the interval length of the grouped blocks is 2.
- a short code length has been exemplified in this description, but it must be taken into consideration that the length of the intrinsic spreading code is considerably large.
- the present invention uses the intrinsic spreading code and the orthogonal codes to increase the data transfer rate without an increase in the whole bandwidth allocated for users, and performs a grouping MLD according to the configuration of the present invention to remarkably reduce the complexity of the MLD system and improve the performance.
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Abstract
Description
Sub-w(1)=(1 1 1 1)→(+ + + +)
Sub-w(2)=(1 0 1 0)→(+ − + −)
Sub-w(3)=(1 1 0 0)→(+ + − −)
Sub-w(4)=(1 0 0 1)→(+ − − +)
C(1)=(+1 +1 +1 +1)
C(2)=(−1 +1 −1 +1)
C(3)=(+1 +1 −1 −1)
C(4)=(+1 −1 −1 +1).
(+2+2+2+2−2−2+2+2)
(−2−2+2+2−2−2−2−2)
(+2+2+2+2+2+2−2−2)
(+2+2−2−2+2+2+2+2)
Rkl=Hk1Skl T+N [Equation 1]
where the diagonal matrix Hk1 is the Rayleigh fading constant of a sub carrier allocated to the grouped block; Skl T is the transposed value of the transmitted sequence; and N is the noise vector.
ej 2=min|Rkl−HkVjl T|2 [Equation 2]
where C is the intrinsic spreading code.
Claims (21)
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KR10-2002-0083746A KR100470401B1 (en) | 2002-12-24 | 2002-12-24 | A wireless communication system and method using grouping Maximum Lilelihood Detection |
US10/729,755 US7366222B2 (en) | 2002-12-24 | 2003-12-04 | Wireless communication system and method using grouping maximum likelihood detection |
US12/759,974 USRE43059E1 (en) | 2002-12-24 | 2010-04-14 | Wireless communication system and method using grouping maximum likelihood detection |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5425050A (en) | 1992-10-23 | 1995-06-13 | Massachusetts Institute Of Technology | Television transmission system using spread spectrum and orthogonal frequency-division multiplex |
US5809060A (en) | 1994-02-17 | 1998-09-15 | Micrilor, Inc. | High-data-rate wireless local-area network |
US5856971A (en) | 1994-05-13 | 1999-01-05 | At&T Corp | Code division multiple access system providing variable data rate access to a user |
US5960032A (en) | 1995-09-20 | 1999-09-28 | The Hong Kong University Of Science & Technology | High speed data transmission using expanded bit durations in multiple parallel coded data streams |
KR100243649B1 (en) | 1997-12-23 | 2000-02-01 | 정선종 | Wideband mobile multimedia transmitter and receiver |
US6041034A (en) | 1996-12-20 | 2000-03-21 | Fujitsu Limited | Spread spectrum communication system |
US6075812A (en) | 1994-02-17 | 2000-06-13 | Micrilor, Inc. | High-data-rate wireless local-area network |
KR20000063968A (en) | 2000-08-14 | 2000-11-06 | 신동관 | Partial Response Signaled - Orthogonal Frequency Division Multiplexing Method and Apparatus |
US6144653A (en) | 1993-11-01 | 2000-11-07 | Telefonakteibolaget Lm Ericsson | Method for communicating in a wireless communication system |
US6161209A (en) | 1997-03-28 | 2000-12-12 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Industry Through The Communications Research Centre | Joint detector for multiple coded digital signals |
US6373861B1 (en) | 1998-12-01 | 2002-04-16 | Samsung Electronics Co, Ltd. | Frequency synchronizing device for OFDM/CDMA system |
US6377632B1 (en) | 2000-01-24 | 2002-04-23 | Iospan Wireless, Inc. | Wireless communication system and method using stochastic space-time/frequency division multiplexing |
KR100340829B1 (en) | 1997-06-20 | 2002-06-20 | 다니구찌 이찌로오, 기타오카 다카시 | Method and device for variable-speed transmission |
US20020122510A1 (en) | 2001-01-04 | 2002-09-05 | Evgeny Yakhnich | Apparatus for and method of converting soft symbol information to soft bit information |
US20020136190A1 (en) * | 2001-03-26 | 2002-09-26 | Yoshiyuki Hata | Band-division demodulation method and OFDM receiver |
US6487255B1 (en) | 1998-08-31 | 2002-11-26 | Ericsson Inc. | Information generation for coherent demodulation of differentially encoded signals |
US7336738B2 (en) * | 2001-06-15 | 2008-02-26 | Sony Corporation | Demodulation timing generation circuit and demodulation apparatus |
-
2002
- 2002-12-24 KR KR10-2002-0083746A patent/KR100470401B1/en active IP Right Grant
-
2003
- 2003-12-04 US US10/729,755 patent/US7366222B2/en not_active Ceased
-
2010
- 2010-04-14 US US12/759,974 patent/USRE43059E1/en active Active
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5425050A (en) | 1992-10-23 | 1995-06-13 | Massachusetts Institute Of Technology | Television transmission system using spread spectrum and orthogonal frequency-division multiplex |
US6144653A (en) | 1993-11-01 | 2000-11-07 | Telefonakteibolaget Lm Ericsson | Method for communicating in a wireless communication system |
US6075812A (en) | 1994-02-17 | 2000-06-13 | Micrilor, Inc. | High-data-rate wireless local-area network |
US5809060A (en) | 1994-02-17 | 1998-09-15 | Micrilor, Inc. | High-data-rate wireless local-area network |
US5856971A (en) | 1994-05-13 | 1999-01-05 | At&T Corp | Code division multiple access system providing variable data rate access to a user |
US5960032A (en) | 1995-09-20 | 1999-09-28 | The Hong Kong University Of Science & Technology | High speed data transmission using expanded bit durations in multiple parallel coded data streams |
KR100254480B1 (en) | 1996-12-20 | 2000-05-01 | 아끼구사 나오유끼 | Spectrum spreading communication system |
US6041034A (en) | 1996-12-20 | 2000-03-21 | Fujitsu Limited | Spread spectrum communication system |
US6161209A (en) | 1997-03-28 | 2000-12-12 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Industry Through The Communications Research Centre | Joint detector for multiple coded digital signals |
US6628667B1 (en) | 1997-06-20 | 2003-09-30 | Mitsubishi Denki Kabushiki Kaisha | Variable rate transmitting method and apparatus using bi-orthogonal functions for variable rate transmission rates above a predetermined value |
KR100340829B1 (en) | 1997-06-20 | 2002-06-20 | 다니구찌 이찌로오, 기타오카 다카시 | Method and device for variable-speed transmission |
KR100243649B1 (en) | 1997-12-23 | 2000-02-01 | 정선종 | Wideband mobile multimedia transmitter and receiver |
US6487255B1 (en) | 1998-08-31 | 2002-11-26 | Ericsson Inc. | Information generation for coherent demodulation of differentially encoded signals |
US6373861B1 (en) | 1998-12-01 | 2002-04-16 | Samsung Electronics Co, Ltd. | Frequency synchronizing device for OFDM/CDMA system |
US6377632B1 (en) | 2000-01-24 | 2002-04-23 | Iospan Wireless, Inc. | Wireless communication system and method using stochastic space-time/frequency division multiplexing |
KR20000063968A (en) | 2000-08-14 | 2000-11-06 | 신동관 | Partial Response Signaled - Orthogonal Frequency Division Multiplexing Method and Apparatus |
US20020122510A1 (en) | 2001-01-04 | 2002-09-05 | Evgeny Yakhnich | Apparatus for and method of converting soft symbol information to soft bit information |
US20020136190A1 (en) * | 2001-03-26 | 2002-09-26 | Yoshiyuki Hata | Band-division demodulation method and OFDM receiver |
US7336738B2 (en) * | 2001-06-15 | 2008-02-26 | Sony Corporation | Demodulation timing generation circuit and demodulation apparatus |
Non-Patent Citations (4)
Title |
---|
Cao, Y.W. et al., "A New Multi-Code/Multi-Carrier DS-CDMA System", Global Telecommunications Conference, 2001, Globecom '01. IEEE, 2001. pp. 543-546, vol. 1. |
Kaiser, Stephen; OFDM-CDMA versus DS-CDMA: Performance Evaluation for Fading Channels, IEEE, 1995, p. 1722-1726. |
Park Kyung Won et al., "MIMO-OFDM Techniques for High-Speed Wireless Transmission" Telecommunication Review, Mar.-Apr. 2002, pp. 210-224, vol. 12. |
Rajappan, G.S. et al., "Rate maximization for multi-code CDMA with optimized signatures", Military Communications Conference, 2001. MILCOM 2001. IEEE, pp. 1375-1379, vol. 2. |
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US20040120415A1 (en) | 2004-06-24 |
KR100470401B1 (en) | 2005-02-05 |
KR20040056995A (en) | 2004-07-01 |
US7366222B2 (en) | 2008-04-29 |
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