WO2007066869A2 - Transmitting apparatus using spread-spectrum transmission method - Google Patents
Transmitting apparatus using spread-spectrum transmission method Download PDFInfo
- Publication number
- WO2007066869A2 WO2007066869A2 PCT/KR2006/002915 KR2006002915W WO2007066869A2 WO 2007066869 A2 WO2007066869 A2 WO 2007066869A2 KR 2006002915 W KR2006002915 W KR 2006002915W WO 2007066869 A2 WO2007066869 A2 WO 2007066869A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- matrix
- transmitting apparatus
- precoding
- spread
- denotes
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
-
- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2201/00—Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
- H04B2201/69—Orthogonal indexing scheme relating to spread spectrum techniques in general
- H04B2201/707—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
- H04B2201/70703—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation using multiple or variable rates
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/10—Code generation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03343—Arrangements at the transmitter end
-
- 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
- H04L5/0001—Arrangements for dividing the transmission path
- H04L5/0014—Three-dimensional division
- H04L5/0016—Time-frequency-code
- H04L5/0021—Time-frequency-code in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
Definitions
- the present invention relates to a transmitting apparatus using a spread-spectrum transmission method, and particularly relates to a transmitting apparatus that uses a new pre-coding algorithm for obtaining a maximum diversity gain in a spread- spectrum transmission system.
- a spread-spectrum transmission scheme distributes symbol transmission into
- a multi-carrier code division multiple access (MC-CDMA) scheme is the most representative spread-spectrum transmission method, and many studies related to the MC- CDMA have been carried out.
- the MC-CDMA employs a Walsh matrix to spread symbols, and a precoding
- W denotes a Walsh matrix
- Figure 2 provides optimal performance when the spread factor has an exponent of 2. That is, the precoding matrix does not provide optimal performance when the spread factor does not have an exponent of 2. Thus, research and studies are under investigation for replacing the precoding method that uses Math Figure 2.
- a transmitting apparatus of a spread-spectrum transmission system uses a new precoding method that can provide a maximum diversity gain.
- An exemplary transmitting apparatus that employs a spread-spectrum transmission scheme according to an embodiment of the present invention includes a precoder.
- the precoder precodes a transmit data signal by using a first matrix and a diagonal matrix, and generates an output signal of the precoding.
- the first matrix includes one of a discrete cosine transform (DCT) matrix, a discrete Hartley transform (DHT) matrix, and a discrete sine transform (DST) matrix.
- DCT discrete cosine transform
- DHT discrete Hartley transform
- DST discrete sine transform
- the precoder generates an output signal responding to the transit data signal by performing a product operation between the first matrix and the diagonal matrix.
- the transmitting apparatus of the spread-spectrum transmission system transmits data by employing the new precoding scheme, thereby obtaining the maximum diversity gain and coding gain.
- a bit error rate (BER) can be more optimized as a spread factor increases.
- FlG. 1 is a block diagram showing a transmitting apparatus using a new precoding scheme in a spread-spectrum transmission system according to an exemplary embodiment of the present invention.
- FlG. 2 to FlG. 4 are graphs respectively showing comparison of signal to noise ratio
- SNR bit error rate
- BER bit error rate
- a module means a unit that performs a specific function or operation, and can be realized by hardware or software, or a combination of both.
- FIG. 1 is a block diagram showing a transmitting apparatus of a spread-spectrum transmission system that uses a new precoding scheme according to an exemplary embodiment of the present invention.
- the transmitting apparatus includes a precoder 100 and an
- IFFT Inverse Fast Fourier Transform
- the precoder 100 precodes a source signal and transmits a precoding result to the
- DCT Discrete Cosine Transform
- DST Discrete Sine Transform
- DHT Discrete Hartley Transform
- the DCT, the DST, and the DHT are included in an orthogonal transformation encoding algorithm that converts a video signal in the time axis into the frequency axis by using a discrete cosine function, a discrete sine function, or a discrete Hartley function as a conversion coefficient.
- the precoder precodes a transmit data signal using the DCT, DST, or DHT matrix rather than using a conventional FFT matrix such that signal to noise ratio (SNR) and bit error rate (BER) are improved as shown in FIG. 2 to FIG. 4.
- SNR signal to noise ratio
- BER bit error rate
- FIG. 2 to FIG. 4 are graphs showing comparison of SNR/BER in data transmission using the precoding scheme of the precoder according to the exemplary embodiment of the present invention and the conventional algebraic method.
- the precoding scheme of the transmitting apparatus provides better SNR and BER compared to a precoding method that uses a conventional algebraic method.
- the graphs of FIG. 2 to FIG. 4 show comparison of SNR/BER of a received signal in data transmission in the case that a conventional algebraic-based precoding method (which is known as the best algebraic method) is used for calculating the SNR/BER and in the case that the DHT matrix among the precoding methods of the precoder is used for calculating the SNR/BER.
- the spreading factor (SF) is respectively set to be 3, 5, and 7.
- the algebraic-based precoding method and the precoding method that uses the conventional FTT matrix have a similar SNR/BER graph.
- the modulation method for data transmission includes Quadrature Phase
- QPSK Quadrature Amplitude Modulation
- 64QAM 64 Quadrature Amplitude Modulation
- the graph of FIG. 2 shows comparison of SNR/BER in data transmitting/receiving in the case of using algebraic-based modulations methods, the QPSK 630, the 16QAM 631, and the 64QAM 632, and SNR/BER in data transmitting/receiving in the case of using the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732.
- the DHT matrix is generated on the basis of Math Figure 7, and the value of the SF is 3.
- the graph of FIG. 3 shows comparison of SNR/BER in the case that algebraic- based modulations methods, the QPSK 630, the 16QAM 631, and the 64QAM 632, are respectively used for data transmitting/receiving and SNR/BER in the case that the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732, are respectively used for data transmitting/receiving.
- the DHT matrix is generated on the basis of Math Figure 7, and the value of the SF is 5.
- FIG. 4 shows comparison of SNR/BER in the case that the algebraic-based
- the QPSK 630, the 16QAM 631, and the 64QAM 632 are respectively used for data transmitting/receiving and SNR/BER in the case that the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732, are respectively used for data transmitting/receiving.
- the DHT matrix is generated on the basis of Math Figure 7, and the value of the SF is 7.
- the precoding method according to the present exemplary embodiment obtains better BER and SNR as the value of the SF increases compared to those obtained by using the conventional algebraic method-based precoding method and the FFT matrix-based precoding method.
- the SNR/BER graph of the precoding method that uses the FFT matrix is similar to those of FIG. 2 and FIG. 3. That is, diversity gain and coding gain can be more improved compared to the prior art, depending on the value of SF.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radio Transmission System (AREA)
Abstract
The present invention relates to a transmitting apparatus using a spread-spectrum transmission scheme. The transmitting apparatus includes a precoder for precoding a data signal by performing a product operation between a first matrix and a diagonal matrix. The precoding outputs a signal responding to the input data by performing a product operation between the first matrix and the diagonal matrix. Such a transmitting apparatus obtains a maximum diversity gain.
Description
Description
TRANSMITTING APPARATUS USING SPREAD-SPECTRUM
TRANSMISSION METHOD
Technical Field
[1] The present invention relates to a transmitting apparatus using a spread-spectrum transmission method, and particularly relates to a transmitting apparatus that uses a new pre-coding algorithm for obtaining a maximum diversity gain in a spread- spectrum transmission system.
Background Art
[2] A spread-spectrum transmission scheme distributes symbol transmission into
several chip levels and spreads them to a time or frequency domain such that a receiving side obtains diversity gain during symbol detection at the receiving side.
[3] A multi-carrier code division multiple access (MC-CDMA) scheme is the most representative spread-spectrum transmission method, and many studies related to the MC- CDMA have been carried out.
[4] The MC-CDMA employs a Walsh matrix to spread symbols, and a precoding
module performs a matrix operation by using the Walsh matrix. Generation of an output signal by using the Walsh matrix is as shown in Math Figure 1.
[5] MathFigure 1
[6] where W denotes a Walsh matrix, c denotes an input source vector c=[cl, c2, ..., cs]
T, and x denotes an output signal x=[xl, x2, ..., xs]T.
[7] However, many studies have proven that there is a limit to obtaining a maximum diversity gain by using the Walsh matrix. In order to improve this limit, a method for obtaining a diversity gain by performing a product operation between the Walsh matrix and a diagonal matrix has been studied.
[8] In addition, a method for generating a precoding matrix by performing a product operation between a unitary Fast Fourier Transform (FFT) matrix and a diagonal matrix has been recently proposed. This precoding method generates an output signal through Math Figure 2.
[9] MathFigure 2
x=F* D*r
[10] where F denotes a FFT matrix and D denotes a diagonal matrix, and
[12] Many studies and research have proven that the precoding matrix using Math
Figure 2 provides optimal performance when the spread factor has an exponent of 2. That is, the precoding matrix does not provide optimal performance when the spread factor does not have an exponent of 2. Thus, research and studies are under investigation for replacing the precoding method that uses Math Figure 2.
[13] Recently, an algebraic-based matrix has been proposed for replacing the precoding matrix, but it has been experimentally proven that the algebraic-based matrix obtains a diversity gain and a coding gain that are similar to those obtained by using the precoding matrix. Therefore, the algebraic-based matrix also has a problem in obtaining a maximum diversity gain and coding gain.
[14] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
Disclosure of Invention
Technical Problem
[15] According to an embodiment of the present invention, a transmitting apparatus of a spread-spectrum transmission system is provided. The transmitting apparatus uses a new precoding method that can provide a maximum diversity gain.
Technical Solution
[16] An exemplary transmitting apparatus that employs a spread-spectrum transmission scheme according to an embodiment of the present invention includes a precoder. The precoder precodes a transmit data signal by using a first matrix and a diagonal matrix, and generates an output signal of the precoding. The first matrix includes one of a discrete cosine transform (DCT) matrix, a discrete Hartley transform (DHT) matrix, and a discrete sine transform (DST) matrix.
[17] The precoder generates an output signal responding to the transit data signal by performing a product operation between the first matrix and the diagonal matrix.
[18]
Advantageous Effects
[19] Accordingly, the transmitting apparatus of the spread-spectrum transmission system transmits data by employing the new precoding scheme, thereby obtaining the maximum diversity gain and coding gain. In addition, a bit error rate (BER) can be more optimized as a spread factor increases.
Brief Description of the Drawings
[20] FlG. 1 is a block diagram showing a transmitting apparatus using a new precoding scheme in a spread-spectrum transmission system according to an exemplary embodiment of the present invention.
[21] FlG. 2 to FlG. 4 are graphs respectively showing comparison of signal to noise ratio
(SNR)/bit error rate (BER) in precoding-based data transmission and SNR/BER in conventional algebraic-based data transmission.
Best Mode for Carrying Out the Invention
[22] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. 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. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
[23] Throughout this specification and the claims which follow, unless explicitly
described to the contrary, the word "comprise/include" or variations such as
"comprises/includes" or "comprising/including" will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
[24] In addition, throughout this specification and the claims which follow, a module means a unit that performs a specific function or operation, and can be realized by hardware or software, or a combination of both.
[25] A transmitting apparatus that provides a new precoding scheme according to an exemplary embodiment of the present invention will now be described with reference to the accompanying drawings.
[26] FIG. 1 is a block diagram showing a transmitting apparatus of a spread-spectrum transmission system that uses a new precoding scheme according to an exemplary embodiment of the present invention.
[27] As shown in FlG. 1, the transmitting apparatus includes a precoder 100 and an
Inverse Fast Fourier Transform (IFFT) module 200.
[28] According to the exemplary embodiment of the present invention, configuration of the transmitting apparatus is partially omitted since it is well known to those skilled in the art.
[29] The precoder 100 precodes a source signal and transmits a precoding result to the
IFFT module 200.
[30] The precoding of the precoder 100 is calculated by the equation x = P * D* r, and P has a value of a Discrete Cosine Transform (DCT) matrix, a Discrete Sine Transform
(DST) matrix, or a Discrete Hartley Transform (DHT) matrix. Herein, x denotes an output of the precoding, r denotes a source c (n) which is an initial signal value, and D denotes a diagonal matrix.
[31] The DCT, the DST, and the DHT are included in an orthogonal transformation encoding algorithm that converts a video signal in the time axis into the frequency axis by using a discrete cosine function, a discrete sine function, or a discrete Hartley function as a conversion coefficient.
[32] Herein, the DCT matrix of P in the exemplary embodiment of the present invention is calculated by Math Figure 3 and Math Figure 4.
[34] where a=l(when n=0) or a= (when n 0).
[36] where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively represent an index of each row and column.
[37] In addition, the DST matrix of P in the exemplary embodiment of the present
invention is calculated by Math Figure 5 and Math Figure 6.
[39] where a=l(when n=S-l) or a= (when n S-I).
[41] where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively represent an index of each row and column.
[42] The DHT matrix of P in the exemplary embodiment of the present invention is calculated by Math Figure 7.
[44] where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively denote an index of each row and column.
[45] The precoder precodes a transmit data signal using the DCT, DST, or DHT matrix rather than using a conventional FFT matrix such that signal to noise ratio (SNR) and bit error rate (BER) are improved as shown in FIG. 2 to FIG. 4. The graphs show the performance comparison in the case of using the DHT matrix.
[46] FIG. 2 to FIG. 4 are graphs showing comparison of SNR/BER in data transmission using the precoding scheme of the precoder according to the exemplary embodiment of the present invention and the conventional algebraic method.
[47] As shown in FIG. 2 to a FIG. 4, the precoding scheme of the transmitting apparatus according to the exemplary embodiment of the present invention provides better SNR and BER compared to a precoding method that uses a conventional algebraic method.
[48] The graphs of FIG. 2 to FIG. 4 show comparison of SNR/BER of a received signal in data transmission in the case that a conventional algebraic-based precoding method (which is known as the best algebraic method) is used for calculating the SNR/BER and in the case that the DHT matrix among the precoding methods of the precoder is used for calculating the SNR/BER. In this comparison, the spreading factor (SF) is respectively set to be 3, 5, and 7. Herein, the algebraic-based precoding method and the precoding method that uses the conventional FTT matrix have a similar SNR/BER graph.
[49] Herein, the modulation method for data transmission includes Quadrature Phase
Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (16QAM), and 64 Quadrature Amplitude Modulation (64QAM).
[50] The graph of FIG. 2 shows comparison of SNR/BER in data transmitting/receiving in the case of using algebraic-based modulations methods, the QPSK 630, the 16QAM 631, and the 64QAM 632, and SNR/BER in data transmitting/receiving in the case of using the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732. At this time, the DHT matrix is generated on the basis of Math Figure 7, and the value of the SF is 3.
[51] The graph of FIG. 3 shows comparison of SNR/BER in the case that algebraic- based modulations methods, the QPSK 630, the 16QAM 631, and the 64QAM 632, are respectively used for data transmitting/receiving and SNR/BER in the case that the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732, are respectively used for data transmitting/receiving. At this time, the DHT matrix
is generated on the basis of Math Figure 7, and the value of the SF is 5.
[52] FIG. 4 shows comparison of SNR/BER in the case that the algebraic-based
modulations methods, the QPSK 630, the 16QAM 631, and the 64QAM 632, are respectively used for data transmitting/receiving and SNR/BER in the case that the DHT matrix-based modulation methods, QPSK 730, the 16QAM 731, and the 64QAM 732, are respectively used for data transmitting/receiving. At this time, the DHT matrix is generated on the basis of Math Figure 7, and the value of the SF is 7.
[53] Based on the comparison graphs, the precoding method according to the present exemplary embodiment obtains better BER and SNR as the value of the SF increases compared to those obtained by using the conventional algebraic method-based precoding method and the FFT matrix-based precoding method. Herein, the SNR/BER graph of the precoding method that uses the FFT matrix is similar to those of FIG. 2 and FIG. 3. That is, diversity gain and coding gain can be more improved compared to the prior art, depending on the value of SF.
[54] The above-described exemplary embodiment of the present invention may be
realized by an apparatus and a method, but it may also be realized by a program that realizes functions corresponding to configurations of the exemplary embodiment or a recording medium that records the program. Such realization can be easily performed by a person skilled in the art.
[55] While this invention has been described in connection with what is presently
considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Claims
[1] A transmitting apparatus that employs a spread-spectrum transmission scheme, the transmitting apparatus comprising a precoder for precoding a transmit data signal by using a first matrix and a diagonal matrix and generating an output signal of the precoding, the first matrix including one of a discrete cosine transform (DCT) matrix, a discrete Hartley transform (DHT) matrix, and a discrete sine transform (DST) matrix.
[2] The transmitting apparatus of claim 1, wherein the precoder generates an output signal responding to the transit data signal by performing a product operation between the first matrix and the diagonal matrix.
[3] The transmitting apparatus of claim 1 or claim 2, wherein the DCT matrix is generated by the following equation:
where a=l(when n=0) or a= (when n 0)
where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively denote an index of each row and column.
[4] The transmitting apparatus of claim 1 or claim 2, wherein the DST matrix is generated by the following equation:
where a=l(when n=S-l) or a= (when n S-I)
where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively denote an index of each row and column.
[5] The transmitting apparatus of claim 1 or claim 2, wherein the DHT matrix is generated by the following equation:
where S denotes a spreading factor, and n= (0, 1, 2,...,s-l) and k= (0, 1, 2,...,s-l) respectively denote an index of each row and column.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/096,870 US20090022209A1 (en) | 2005-12-10 | 2006-07-25 | Transmitting apparatus using spread-spectrum transmission method |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR20050121356 | 2005-12-10 | ||
KR10-2005-0121356 | 2005-12-10 | ||
KR1020060026019A KR100669154B1 (en) | 2005-12-10 | 2006-03-22 | A transmitting apparatus in spread-spectrum transmission method |
KR10-2006-0026019 | 2006-03-22 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2007066869A2 true WO2007066869A2 (en) | 2007-06-14 |
WO2007066869A3 WO2007066869A3 (en) | 2008-08-07 |
Family
ID=38123302
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/KR2006/002915 WO2007066869A2 (en) | 2005-12-10 | 2006-07-25 | Transmitting apparatus using spread-spectrum transmission method |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2007066869A2 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19616829C1 (en) * | 1996-04-26 | 1997-04-24 | Siemens Ag | Radio transfer system for digital signals between several subscriber terminals and base station |
DE19647833A1 (en) * | 1996-11-19 | 1998-05-20 | Deutsch Zentr Luft & Raumfahrt | Method for the simultaneous radio transmission of digital data between several subscriber stations and a base station |
-
2006
- 2006-07-25 WO PCT/KR2006/002915 patent/WO2007066869A2/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19616829C1 (en) * | 1996-04-26 | 1997-04-24 | Siemens Ag | Radio transfer system for digital signals between several subscriber terminals and base station |
DE19647833A1 (en) * | 1996-11-19 | 1998-05-20 | Deutsch Zentr Luft & Raumfahrt | Method for the simultaneous radio transmission of digital data between several subscriber stations and a base station |
Also Published As
Publication number | Publication date |
---|---|
WO2007066869A3 (en) | 2008-08-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3999271B2 (en) | Reduction of average power-to-peak ratio in multi-carrier modulation systems | |
WO2018050044A1 (en) | Non-orthogonal multiple access transmission | |
US5862182A (en) | OFDM digital communications system using complementary codes | |
US6314146B1 (en) | Peak to average power ratio reduction | |
TWI405429B (en) | Apparatus for transmitting data using carriers and method thereof | |
US20160277747A1 (en) | Chirp spread spectrum system and method | |
US11025470B2 (en) | Communication system and method using orthogonal frequency division multiplexing (OFDM) with non-linear transformation | |
JPH10107762A (en) | Data processing method, transmitter and receiver | |
US20100226449A1 (en) | Method and System for Reducing the Peak-to-Average Power Ratio | |
US9112757B2 (en) | Communication device and communication method | |
CN102957514A (en) | Encryption algorithm of encryption OFDM (Orthogonal Frequency Division Multiplexing) based on discrete Hartley transform | |
US8059764B2 (en) | Systems and methods for low-complexity max-log MIMO detection | |
US20090022209A1 (en) | Transmitting apparatus using spread-spectrum transmission method | |
CN112929057A (en) | Dual generalized spatial modulation method and system | |
Elavarasan et al. | Peak-power reduction using improved partial transmit sequence in orthogonal frequency division multiplexing systems | |
EP2269352B1 (en) | Techniques for multiple-subcarrier joint precoding | |
WO2007066869A2 (en) | Transmitting apparatus using spread-spectrum transmission method | |
US20100329376A1 (en) | Method for accelerating the precoding and pre-decoding of symbols in ofdm systems | |
JP4288378B1 (en) | Data communication system, data decoding apparatus and method | |
Liang et al. | Improving the peak-to-average power ratio of single-carrier frequency division multiple access systems by using an improved constellation extension scheme with error correction | |
CN112688726B (en) | Polarized spectrum pre-coded transmission | |
KR101215932B1 (en) | Method of PAPR reduction for OFDM system using additive mapping sequences and apparatus for the same | |
CN109936428B (en) | Information processing method, device, equipment and computer readable storage medium | |
Omer et al. | Adaptive hybrid PAPR reduction in OFDM system | |
KR100810144B1 (en) | Apparatus for PAR reduction in orthogonal frequency division multiplexing system and method therof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 12096870 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 06798524 Country of ref document: EP Kind code of ref document: A2 |