KR20130073528A - Phase rotation modulation apparatus and method - Google Patents

Phase rotation modulation apparatus and method Download PDF

Info

Publication number
KR20130073528A
KR20130073528A KR1020110141419A KR20110141419A KR20130073528A KR 20130073528 A KR20130073528 A KR 20130073528A KR 1020110141419 A KR1020110141419 A KR 1020110141419A KR 20110141419 A KR20110141419 A KR 20110141419A KR 20130073528 A KR20130073528 A KR 20130073528A
Authority
KR
South Korea
Prior art keywords
symbol
phase
phase rotation
symbols
odd
Prior art date
Application number
KR1020110141419A
Other languages
Korean (ko)
Inventor
오정열
김대호
박남훈
Original Assignee
한국전자통신연구원
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 한국전자통신연구원 filed Critical 한국전자통신연구원
Priority to KR1020110141419A priority Critical patent/KR20130073528A/en
Publication of KR20130073528A publication Critical patent/KR20130073528A/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H04L27/3845—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier
    • H04L27/3854—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier using a non - coherent carrier, including systems with baseband correction for phase or frequency offset
    • H04L27/3872—Compensation for phase rotation in the demodulated signal

Abstract

PURPOSE: A phase rotation modulation & demodulation apparatus and a method thereof are provided to prevent degradation of reception performance, and to obtain high electricity of a transmitter. CONSTITUTION: A transmitting apparatus comprises: a bit grouping (100), a phase rotation symbol mapper (110), an up-sampler (120), a transmission filter (130), a digital analog converter (140), and an orthogonal modulator (150). The bit grouping performs a k bit grouping to map an input bit string into a symbol having M level. The phase rotation symbol mapper is inputted with the k bit, and produces a complex symbol having a phase rotational characteristic. The up-sampler performs an up-sampling of the phase rotation encoded symbol. The transmission filter filters the up-sampled signal. The digital analog converter generates a radio transmission signal by converting a digital signal to an analog signal and passing through the orthogonal modulator. [Reference numerals] (100) Bit grouping; (110) Phase rotation symbol mapper; (120) Up-sampler; (130) Transmission filter; (140) Digital analog converter; (150) Orthogonal modulator

Description

PHASE ROTATION MODULATION APPARATUS AND METHOD}

Embodiments of the present invention relate to a phase rotation modulation and demodulation device and method for performing modulation and demodulation through phase rotation.

In recent years, wireless communication systems have increased demand for low power characteristics as well as data communication speed. In particular, the mobile communication system uses multiple modulation and demodulation, and has a disadvantage in that the peak to average power ratio (PAPR), which is the maximum power to average power ratio, becomes very large. This high PAPR characteristic causes an increase in back-off due to a nonlinear characteristic of a high power amplifier (HPA), which causes an increase in power consumption. Phase Shift Keying and Quadrature Amplitude Modulation (QAM), which modulate with phase and amplitude magnitude, have been widely used in recent communication methods because of their excellent spectral efficiency and reception performance. However, QAM modulation has a disadvantage in that it is difficult to reduce power due to spectral distortion occurring in nonlinear devices.

An embodiment of the present invention is to provide a phase rotation modulation and demodulation device and method that can obtain a high power efficiency of the transmitter by reducing the distortion of the signal due to the non-linear characteristics generated in the phase modulation scheme and amplitude modulation scheme in a wireless communication system.

According to an embodiment of the present invention, the phase rotation modulation apparatus modulates a symbol by using a symbol mapper having a phase difference from each other by dividing a transmitting symbol into even and odd symbols. In this way, the phase rotation modulator can be applied not only to the phase shift keying (PSK) method but also to the quadrature amplitude modulation (QAM) method, and to induce phase rotation for each symbol to reduce the PAPR of the transmitted signal and the reception performance is not degraded at all. .

In addition, the phase rotation modulation apparatus according to an embodiment of the present invention includes a bit grouping for grouping the input bit stream by symbol unit; A phase rotation symbol mapper for generating a phase rotated symbol based on the grouped symbols; An upsampler for upsampling the generated symbol; A transmission filter for filtering the upsampled signal; A digital analog converter for converting the filtered symbol into an analog signal; And an orthogonal modulator for orthogonally modulating the analog converted signal to a radio frequency.

In addition, the phase rotation symbol mapper according to an embodiment of the present invention includes a generator for generating a symbol through a symbol mapper in which even and odd symbols have constellation points of different symbols.

In addition, the phase rotation symbol mapper according to an embodiment of the present invention has a constant phase difference between the even and odd symbol mappers to generate a symbol having a different phase constellation point between the even and odd symbols. Contains builders that create mapping tables.

In addition, the phase rotation symbol mapper according to an embodiment of the present invention includes a rotator having a different phase constellation point between even and odd symbols by giving a phase rotation to even or odd symbols through one symbol mapping table. do.

According to an embodiment of the present invention, a phase rotation demodulation device comprises: an orthogonal demodulation unit for converting an input radio frequency received signal into a baseband signal; An analog-digital converter for converting the baseband signal into a digital signal; A reception filter for filtering the digitally converted signal; A synchronization unit for acquiring reception synchronization; A phase rotation unit for channel compensating a received sample value and removing phase differences between even and odd symbols; A signal detection unit detecting a signal of the phase rotation unit; And bit degrouping for converting bits in symbol units into bit strings.

In addition, the phase rotation unit according to an embodiment of the present invention includes a first reverse rotor for removing the phase difference between the even and odd symbols by rotating the phase of the even or odd symbols while performing the channel compensation to the symbol .

In addition, the phase rotation unit according to an embodiment of the present invention includes a second reverse rotor for removing the phase difference between the even and odd symbols by rotating the phase of the even or odd symbols after performing the channel compensation . In detail, the phase rotation unit requires both reverse rotation for channel compensation and reverse rotation for phase rotation. Since the phase rotation unit knows the amount of reverse rotation for phase rotation in advance, it will not rotate the phase twice by performing channel compensation in consideration of the reverse rotation for channel compensation.

According to an embodiment of the present invention, the PAPR size is compared when the rolloff coefficient of the phase filter (PR-QPSK, PR-16QAM, PR-64QAM) and the conventional QPSK, 16QAM, 64QAM transmission filter is 0.3 The PR-QPSK method has about 0.7 dB gain over the QPSK method, the PR-16QAM method has about 0.6 dB gain over the 16QAM method, and the PR-64QAM method has about 0.3 dB gain over the 64QAM method.

In addition, according to an embodiment of the present invention, the transmission and reception apparatus using the phase rotation modulation method can be implemented without increasing the complexity compared to the conventional receiving structure.

1 is a block diagram illustrating an apparatus for transmitting a wireless communication system according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a detailed configuration of the phase rotation symbol mapper of FIG. 1.
3 is a block diagram illustrating a receiving apparatus of a wireless communication system according to an embodiment of the present invention.
4 is a block diagram illustrating a detailed configuration of the phase rotation unit of FIG. 3.
5 is an exemplary diagram illustrating constellation points of symbols according to a conventional QPSK modulation scheme.
6 is an exemplary diagram illustrating constellation points of symbols according to the PR-QPSK modulation scheme of the present invention.
7 is an exemplary diagram illustrating constellation points of symbols according to the PR-16QAM modulation scheme of the present invention.
8 is an exemplary diagram illustrating constellation points of symbols according to the PR-64QAM modulation scheme of the present invention.
9 is a graph comparing PAPRs of various modulation schemes according to the related art and modulation schemes according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

Hereinafter, an apparatus and method for phase rotation demodulation according to an embodiment of the present invention will be described with reference to the accompanying drawings.

7 shows the constellation point of a conventional Quadrature Phase Shift Keying (QPSK) symbol. In the conventional method, a phase difference between symbols occurs by a maximum of 180 degrees ([pi]). The larger the phase difference between symbols, the larger the peak to average power ratio (PAPR), which increases the back-off due to the nonlinear nature of the high power amplifier (HPA) in the transmitter. This is a major factor in increasing transmitter power consumption. For this reason, many modulation schemes have been proposed to reduce the transmission signal PAPR size. For example, the π / 4-DQPSK (Differential Quadrature Phase Shift Keying) method rotates the phase by π / 4 per symbol and transmits information by transmitting the information on the phase difference between symbols. This reduces the phase difference between the maximum symbols within 180 degrees (3π / 4) and reduces the PAPR of the transmission signal by 0.5 dB. In addition, since the information is transmitted to the phase difference between symbols, the synchronization unit has a simple advantage through asynchronous demodulation for recovering a symbol using only the phase difference between front and rear symbols at the receiver. However, such a demodulation method has a disadvantage in that when a symbol error occurs in the receiver, it affects the next symbol demodulation and thus the reception performance is degraded. In addition, such a differential symbol modulation between the symbols can be applied only to the PSK (Phase Shift Keying) method, it can not be applied to the multilevel QAM (Quadrature Amplitude Modulation) method for high-speed data transmission. The modulation scheme proposed in the present invention can be applied not only to the PSK scheme but also to the QAM scheme. In addition, we propose a phase rotation modulation method that induces phase rotation for each symbol to reduce the PAPR of the transmitted signal and does not degrade reception performance at all.

1 is a block diagram showing a transmission apparatus according to an embodiment of the present invention. The transmitter shown in FIG. 1 includes a bit grouping 100, a phase rotation symbol mapper 110, an up-sampler 120, and a transmission filter ( 130, a digital-to-analog converter 140, and a quadrature modulator 150.

The bit grouping 100 performs k (log2M) bit grouping to map the input bit string {a n } into one symbol having the M level.

The phase rotation symbol mapper 110 receives the k-bit input and generates a complex symbol {d i, n , d q, n } having a phase rotation characteristic. The phase rotation symbol mapper 110 performs symbol mapping on the even symbol and the odd symbol through different symbol mappers. For example, in the case of the QPSK modulation method, symbol mapping may be performed as shown in Tables 1 and 2. The mapping variable of Table 2 is a phase rotation of -π / 4 to the mapping variable of Table 1.

FIG. 8A illustrates the constellation points of the QPSK even-numbered symbols on the complex plane. FIG. 8B shows the constellation points of the QPSK odd-numbered symbols on the complex plane. Even and odd symbols occur alternately during the entire symbol period.

Figure pat00001

Table 1 shows an embodiment of a QPSK symbol mapping table of even-numbered symbols.

Figure pat00002

Table 2 shows an embodiment of a QPSK symbol mapping table of odd symbols.

As a method for generating a symbol having a different phase constellation point between even and odd symbols, a symbol mapper having a constant phase difference between even and odd symbols as described above may be used, and the same result may be obtained. Alternatively, a single mapper may be used to perform phase rotation on even or odd symbols after symbol mapping.

FIG. 2 is a block diagram illustrating a detailed configuration of the phase rotation symbol mapper of FIG. 1.

Referring to FIG. 2, the phase rotation symbol mapper includes a generator 210, a builder 220, and a rotor 230.

The generator 210 generates a symbol through a symbol mapper in which even and odd symbols have constellation points of different symbols.

The generator 220 generates a symbol mapping table with a constant phase difference between the even and odd symbol mappers to generate a symbol having a different phase constellation point between the even and odd symbols.

The rotor 230 gives a phase rotation to even or odd symbols through one symbol mapping table to have different phase constellation points between even and odd symbols.

In another embodiment, in actual implementation of the phase rotation symbol mapper, a procedure of a generator, a writer, and a rotator may not be performed to achieve the same effect with minimal operation. As shown in FIG. 3, the phase rotation mapper has a block for determining whether the current input sequence is an even number or an odd number, and there may be a method of selectively using two tables, or as shown in FIG. As such, there may be a way to phase rotate the result with one table. Both methods do not introduce much complexity in mapping symbols with tables.

The phase rotate coded symbol {d n } performs up-sampling in the up-sampler 120. The upsampled signal generates filtered signal {d i , k , d q , k } using transmit shaping filter 130. As an example of the transmission shaping filter, a square root raised cosine filter may be employed. The PAPR of the transmission signal is changed according to the roll-off coefficient of this transmission filter. Therefore, how to determine the rolloff coefficient of the transmission filter is an important factor in the transmitter design.

The digital analog converter 140 converts the digital signal into an analog signal and then generates a wireless transmission signal through the quadrature modulator 150.

Even in the case of 16QAM, symbol mapping tables having different phase differences may be generated as shown in Tables 1 and 2, and may be shown on a complex plane as shown in FIG. 9. 9 (a) shows the constellation points of the 16QAM even-numbered symbols on the complex plane. When the phase is rotated by π / 4, constellation points of odd-numbered symbols as shown in FIG. 9B can be generated. Even-numbered symbols and odd-numbered symbols alternately occur during the entire symbol period. Similarly, it can be applied to 64QAM modulation. FIG. 10A illustrates the constellation points of the 16QAM even-numbered symbols in the complex plane. When the phase rotation is performed by π / 4, constellation points of the odd-numbered symbols as shown in FIG. 10B may be generated. Even-numbered symbols and odd-numbered symbols alternately occur during the entire symbol period.

5 is a block diagram of a receiving apparatus according to an embodiment of the present invention. According to an embodiment of the present invention, a receiving apparatus includes an orthogonal demodulator 300, an analog-digital converter 310, a receive matched filter 320, a synchronizer 330, a phase rotation unit 340, and a signal detector 350. Bit degrouping 360.

The signal {s (t)} transmitted from the transmitter is applied with noise and frequency error through the wireless channel. The signal received by the receiver may be expressed as in Equation 1.

Figure pat00003

From here

Figure pat00004
Is a synthesized phase signal under the influence of mismatch by local oscillator error,
Figure pat00005
The
Figure pat00006
It is a complex Gaussian white noise with power spectral density.

Signal received on receiver

Figure pat00007
Is converted into a baseband signal by the orthogonal demodulation unit 300 and converted into a digital signal by the analog-to-digital converter 310 and then passed through the matching filter 320. The received signal converted into a digital signal may be expressed as Equation 2.

Figure pat00008

From here

Figure pat00009
Is the effect of carrier frequency offset,
Figure pat00010
Is the initial phase offset uniformly distributed from 0 to 2π. The synchronizer 330 performs a function of obtaining the correct synchronization of the received symbol. It estimates the timing synchronization and frequency and phase offset of the symbol. Many algorithms and methods for accurate acquisition are proposed. The phase rotation unit 340 performs the reverse rotation with respect to the phase rotation performed by the transmitter as well as compensation for the magnitude and phase error caused by the influence of the channel obtained by the synchronization unit. In an embodiment, if the odd-numbered symbol has been phase-rotated by -π / 4, the transmitter performs phase rotation on the odd-numbered symbol of the received symbol by π / 4 to restore it back to its original state.

In this case, as a method for reducing the complexity, a value obtained by multiplying the compensation value of the channel estimation by the phase value for reverse phase rotation may be applied to an odd number and performed without increasing hardware.

Figure pat00011

From here

Figure pat00012
Is the channel estimation compensation value for the nth symbol,
Figure pat00013
Is a phase value for reverse phase rotation of an odd numbered symbol. According to the embodiment, the phase is rotated by -π / 4 in the transmitter.
Figure pat00014
Is π / 4, which is a complex value
Figure pat00015
to be.

FIG. 6 is a block diagram illustrating a detailed configuration of the phase rotation unit of FIG. 5.

Referring to FIG. 6, the phase rotation unit includes a first reverse rotor 410 and a second reverse rotor 420.

The first reverse rotor 410 reverses the phase of the even or odd symbol while performing channel compensation on the symbol to remove the phase difference between the even and odd symbols.

The second reverse rotor 420 performs channel compensation on the symbol and then reverses the phase of the even or odd symbol to remove the phase difference between the even and odd symbols.

The received signal whose channel and phase are compensated by the phase rotating unit 340 detects a symbol in the signal detector 350. As a detection method, in the case of a QPSK signal as in the embodiment, the symbol value is determined according to the phase value of the symbol.In the case where information is modulated both in phase and amplitude in the symbol such as QAM modulation, the symbol is determined according to the phase and amplitude size. Demodulate the value of. In the case of the above embodiment, the value of the transmission symbol is demodulated through the demodulation table of the symbol detector shown in Table 3. The signal reconstructed through the demodulation table is reconstructed into a bit signal through bit degrouping 360.

Figure pat00016

Table 3 is a demodulation table of the detector.

11 compares the PAPR size according to the roll-off coefficient of the transmission filter between the phase rotation modulation method (PR-QPSK, PR-16QAM, PR-64QAM) of the present invention and the conventional QPSK, 16QAM, 64QAM method. have. When the rolloff coefficient is 0.3, when comparing the PAPR size, the PR-QPSK method has about 0.7 dB gain than the QPSK method, the PR-16QAM method has about 0.6 dB gain than the 16QAM method, and the PR-64QAM method is 0.3 than the 64QAM method. There is a gain of about dB.

Further, embodiments of the present invention include a computer readable medium having program instructions for performing various computer implemented operations. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

As described above, the present invention has been described by specific embodiments such as specific components and the like. For those skilled in the art, various modifications and variations are possible from these descriptions. It is therefore to be understood that within the scope of the appended claims, 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. .

100: bit grouping
110: phase rotation symbol mapper
120: upsampler
130: transmission filter
140: digital-to-analog converter
150: orthogonal modulator

Claims (1)

Generator to generate a symbol through a symbol mapper with even and odd symbols having constellation points of different symbols, even and odd numbers to produce symbols with different phase constellation points between even and odd symbols A builder that creates a symbol mapping table with a constant phase difference between the first symbol mapper, and gives a phase rotation to even or odd symbols through one symbol mapping table to have different phase constellation points between even and odd symbols. A modulator comprising a rotor; And
A first inverse rotator that reverses the phase of an even or odd symbol while performing channel compensation on a symbol to remove a phase difference between an even and odd symbol, and performs an even or odd number after performing channel compensation on a symbol. A demodulator comprising a second reverse rotor that reverses the phase of the symbol to remove the phase difference between the even and odd symbols
Phase rotation modulation and demodulation device comprising a.
KR1020110141419A 2011-12-23 2011-12-23 Phase rotation modulation apparatus and method KR20130073528A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110141419A KR20130073528A (en) 2011-12-23 2011-12-23 Phase rotation modulation apparatus and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110141419A KR20130073528A (en) 2011-12-23 2011-12-23 Phase rotation modulation apparatus and method

Publications (1)

Publication Number Publication Date
KR20130073528A true KR20130073528A (en) 2013-07-03

Family

ID=48987965

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020110141419A KR20130073528A (en) 2011-12-23 2011-12-23 Phase rotation modulation apparatus and method

Country Status (1)

Country Link
KR (1) KR20130073528A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101479061B1 (en) * 2013-10-02 2015-01-07 경북대학교 산학협력단 Apparatus and method for receiving and transmitting signal
CN104467927A (en) * 2014-11-17 2015-03-25 四川九洲电器集团有限责任公司 Method and device for compensating phases of receive channel
KR20180062133A (en) * 2016-11-30 2018-06-08 성균관대학교산학협력단 Method of pahse rotation shift keying based on probability of bit sequence and apparatus for performing the same, and method of quadrature amplitude pahse rotation modualtion and apparatus for performing the same
KR20180116182A (en) * 2018-10-15 2018-10-24 성균관대학교산학협력단 Method of quadrature amplitude pahse rotation modualtion and apparatus for performing the same
WO2020186424A1 (en) 2019-03-18 2020-09-24 Zte Corporation Systems and methods for conjugate data modulation
CN114070698A (en) * 2020-08-10 2022-02-18 华为技术有限公司 Data transmitting and receiving method and device

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101479061B1 (en) * 2013-10-02 2015-01-07 경북대학교 산학협력단 Apparatus and method for receiving and transmitting signal
CN104467927A (en) * 2014-11-17 2015-03-25 四川九洲电器集团有限责任公司 Method and device for compensating phases of receive channel
CN104467927B (en) * 2014-11-17 2018-04-10 四川九洲电器集团有限责任公司 It is a kind of to be used to compensate the method and device for receiving channel phase
KR20180062133A (en) * 2016-11-30 2018-06-08 성균관대학교산학협력단 Method of pahse rotation shift keying based on probability of bit sequence and apparatus for performing the same, and method of quadrature amplitude pahse rotation modualtion and apparatus for performing the same
KR20180116182A (en) * 2018-10-15 2018-10-24 성균관대학교산학협력단 Method of quadrature amplitude pahse rotation modualtion and apparatus for performing the same
WO2020186424A1 (en) 2019-03-18 2020-09-24 Zte Corporation Systems and methods for conjugate data modulation
EP3942877A4 (en) * 2019-03-18 2022-03-23 ZTE Corporation Systems and methods for conjugate data modulation
CN114070698A (en) * 2020-08-10 2022-02-18 华为技术有限公司 Data transmitting and receiving method and device

Similar Documents

Publication Publication Date Title
KR20130073528A (en) Phase rotation modulation apparatus and method
CN102246437A (en) Communication system and method with signal constellation
JP6577800B2 (en) Single carrier transmission device and reception device
JP3166705B2 (en) Wireless device and transmission method
WO2010093012A1 (en) Receiver apparatus, communication system, reception method and communication method
US7254189B1 (en) Blind carrier offset detection for quadrature modulated digital communication systems
US8971450B2 (en) Transmission device, reception device, transmission method and reception method for wireless communication system
CN112398770A (en) Bluetooth low-power-consumption multiphase frequency shift keying modulation and demodulation method and equipment
US7471743B2 (en) Systems and methods for high-efficiency transmission of information through narrowband channels
KR101289889B1 (en) Transmiiting device, receiving device, transmitting method and receiving method for wireless communication system
KR101470592B1 (en) Data transmission apparatus and data transmission method for inserting of additional data at data modulation, and data reconstitution apparatus and data reconstitution method for separately processing data
CN114338334B (en) Pseudo code pilot frequency-based phase noise estimation and compensation method
KR20130022286A (en) Offset phase rotation shift keying modulation apparatus and method, phase silence rotation shift keying modulation apparatus and method, and phase silence rotation shift keying demodulation apparatus and method
KR20150081993A (en) Method for transmitting and receiving signal in OFDM system and apparatus thereof
US7359452B2 (en) Systems and methods for designing a high-precision narrowband digital filter for use in a communications system with high spectral efficiency
CN102948095B (en) The modulation-demo-demodulation method of ofdm signal, modulation-demodulation device and communicator
Galvão et al. Bandwidth efficient gaussian minimum frequency-shift keying approach for software defined radio
JP6753394B2 (en) Transmitters and methods, and programs
US7269230B2 (en) Systems and methods for designing a high-precision narrowband digital filter for use in a communications system with high spectral efficiency
Udawant et al. Digital image processing by using GMSK
JP4728455B1 (en) Receiving apparatus and receiving method
JP4150284B2 (en) Orthogonal frequency division multiplex transmission apparatus, orthogonal frequency division multiplex transmission method, orthogonal frequency division multiplex transmission program and orthogonal frequency division multiplex reception apparatus, orthogonal frequency division multiplex reception method, orthogonal frequency division multiplex reception program
JPH11243434A (en) Modulation system and radio communication system using the same
JP3611995B2 (en) Digital wireless communication apparatus and method
CN116132230A (en) Phase noise compensation method for polarization multiplexing OFDM-OQAM system

Legal Events

Date Code Title Description
WITN Withdrawal due to no request for examination