Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers. Platform: |
Size: 1265450 |
Author:吴大亨 |
Hits:
Description: We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers. Platform: |
Size: 1265664 |
Author:吴大亨 |
Hits:
Description: 在无线网络的接收机端，对16进制的正交幅度调制信号进行软解调， 这种软解调方式比硬解调会提高2-3dB-Receiver in the wireless network client on the 16-band signal of the quadrature amplitude modulation demodulator soft, this soft than hard demodulation demodulator will increase 2-3dB Platform: |
Size: 198656 |
Author:白雪 |
Hits:
Description: 利用matlab仿真软件，实现8QAM调制。在实现时采用正交调幅的方式,某星座点在I坐标上的投影去调制同相载波的幅度,在Q坐标上的投影去调制正交载波的幅度,然后将2个调幅信号相加就是所需的调相信号。-Use of matlab simulation software to achieve 8QAM modulation. In achieving the adoption of quadrature amplitude modulation means of a constellation in the I coordinates of the projection to the modulation of the amplitude-phase carrier, in the Q coordinates of the projection to the range of carrier orthogonal modulation, and then the sum of two AM signals is the required phase modulation signal. Platform: |
Size: 1024 |
Author:yanyan |
Hits:
Description: 【摘 要】为了减少集成电路硬件复杂度，针对QAM 调制软件实现速度慢的问题，在分析MQAM 调制原理的基础上，采用
直接频率合成实现正余弦信号及无时延改进的滤波器编程方法，提出一种快速实现MQAM 调制算法的软件编程思想，并以
TMS320C55X 为平台[1，4]，将MQAM 调制算法进行了C 编程实现。结果表明：该编程方法能快速产生MQAM 调制信号。
【关键词】多电平正交幅度调制；脉冲成形滤波器；直接频率合成；数字信号处理-【Abstract】 In order to reduce the hardware complexity of integrated circuits for QAM modulation problems of slow software in the analysis based on the principle of MQAM modulation, using
Direct Synthesis of positive cosine signal and non-delay filter to improve programming method is proposed to achieve a fast MQAM modulation algorithm for software programming ideas and to
TMS320C55X as a platform [1,4], will be carried out MQAM modulation algorithm for C programming. The results show: The programming method can rapidly produce MQAM modulation signal.
Key words multi-level quadrature amplitude modulation pulse shaping filter direct frequency synthesizer digital signal processing Platform: |
Size: 877568 |
Author:yanyan |
Hits:
Description: An 8-QAM communications channel simulation in Simulink, constructed from a 16-QAM model and using an I,Q correlation receiver.
QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. QAM is used with pulse amplitude modulation (PAM) in digital systems, especially in wireless applications. In a QAM signal, there are two carriers, each having the same frequency but differing in phase by 90 degrees (one quarter of a cycle, from which the term quadrature arises). One signal is called the ‘I’ signal, and the other is called the ‘Q’ signal. Mathematically, one of the signals can be represented by a sine wave, and the other by a cosine wave. The two modulated carriers are combined at the source for transmission. At the destination, the carriers are separated, the data is extracted from each, and then the data is combined into the original modulating information. -An 8-QAM communications channel simulation in Simulink, constructed from a 16-QAM model and using an I,Q correlation receiver.
QAM (quadrature amplitude modulation) is a method of combining two amplitude-modulated (AM) signals into a single channel, thereby doubling the effective bandwidth. QAM is used with pulse amplitude modulation (PAM) in digital systems, especially in wireless applications. In a QAM signal, there are two carriers, each having the same frequency but differing in phase by 90 degrees (one quarter of a cycle, from which the term quadrature arises). One signal is called the ‘I’ signal, and the other is called the ‘Q’ signal. Mathematically, one of the signals can be represented by a sine wave, and the other by a cosine wave. The two modulated carriers are combined at the source for transmission. At the destination, the carriers are separated, the data is extracted from each, and then the data is combined into the original modulating information. Platform: |
Size: 11264 |
Author:Griffin Wright |
Hits:
Description: Quadrature amplitude modulation (QAM) is a modulation scheme in which two sinusoidal carriers,
one exactly 90 degrees out of phase with respect to the other, are used to transmit data over
a given physical channel. One signal is called the I signal, and the other is called the Q signal.
Because the orthogonal carriers occupy the same frequency band and differ by a 90 degree phase
shift, each can be modulated independently, transmitted over the same frequency band, and
separated by demodulation at the receiver. For a given available bandwidth, QAM enables data
transmission at twice the rate of standard pulse amplitude modulation (PAM) without any degradation
in the bit error ratio (BER). Platform: |
Size: 508928 |
Author:Flo |
Hits:
Description: Quadrature amplitude modulation (QAM) is a modulation scheme in which two sinusoidal carriers,
one exactly 90 degrees out of phase with respect to the other, are used to transmit data over
a given physical channel. One signal is called the I signal, and the other is called the Q signal.
Because the orthogonal carriers occupy the same frequency band and differ by a 90 degree phase
shift, each can be modulated independently, transmitted over the same frequency band, and
separated by demodulation at the receiver. For a given available bandwidth, QAM enables data
transmission at twice the rate of standard pulse amplitude modulation (PAM) without any degradation
in the bit error ratio (BER). Platform: |
Size: 3072 |
Author:Flo |
Hits:
Description: Inter-symbol interference if not taken care off may
cause severe error at the receiver and the detection of signal becomes
difficult. An adaptive equalizer employing Recursive Least Squares
algorithm can be a good compensation for the ISI problem. In this
paper performance of communication link in presence of Least Mean
Square and Recursive Least Squares equalizer algorithm is analyzed.
A Model of communication system having Quadrature amplitude
modulation and Rician fading channel is implemented using
MATLAB communication block set. Bit error rate and number of
errors is evaluated for RLS and LMS equalizer algorithm, due to
change in Signal to Noise Ratio (SNR) and fading component gain in
Rician fading Channel. Platform: |
Size: 400384 |
Author:pravin jadhav |
Hits:
Description: 利用matlab仿真软件，实现8QAM调制。在实现时采用正交调幅的方式,某星座点在I坐标上的投影去调制同相相载波的幅度,在Q坐标上的投影去调制正交载波的幅度,然后将2个调幅信号相加就是所需的调相信号。 已通过测试。
-Matlab simulation software to achieve 8QAM modulation. Implemented using quadrature amplitude modulation, phase carrier amplitude modulated by a constellation point in the projection coordinates, projection amplitude modulated orthogonal carriers in the coordinates of Q, then the sum of two amplitude modulated signals the required phase modulation signal. Has been tested. Platform: |
Size: 1024 |
Author:清醒 |
Hits:
Description: B_Q_Q16_AWGN.rar是BPSK,QPSK,16QAM在高斯信道下的系统性能仿真，给出了信噪比SNR与误比特率BER 的关系。
16QAM是16进制的正交振幅调制在高斯信道和瑞利信道下的信噪比SNR与误比特率BER 的关系。都是matlab编写的-B_Q_Q16_AWGN.rar BPSK, QPSK, 16QAM in AWGN channel system performance simulation, given the relationship between the SNR and bit error rate (BER). 16QAM is the relationship between the 16-ary quadrature amplitude modulation signal to noise ratio SNR in the Gaussian channel and Rayleigh channel and the bit error rate (BER). Matlab prepared Platform: |
Size: 15360 |
Author:张帆 |
Hits:
Description: 16 进制的正交振幅调制是一种振幅相位联合键控信号。16QAM 的产生有 2 种方法：
（1）正交调幅法，它是有 2 路正交的四电平振幅键控信号叠加而成；
（2）复合相移法：它是用 2 路独立的四相位移相键控信号叠加而成。-Quadrature amplitude modulation is a hex key signal amplitude and phase combined. 16QAM produce two kinds of methods: (1) quadrature amplitude modulation method, which is four-level quadrature amplitude shift keying signal 2 superposition (2) composite phase shift method: it is with 2 independent quadrature phase shift keying signal superposition. Platform: |
Size: 10240 |
Author:kai |
Hits:
Description: Generation of ASK:
Amplitude shift keying - ASK - in the context of digital communication is a modulation process which imparts to a sinusoid two or more discrete amplitude levels 1. These are related to the number of levels adopted by the digital message. For a binary message sequence, there are two levels one of which is typically zero. Thus the modulated waveform consists of bursts of a sinusoid.
Demodulation of ASK:
ASK signal has a well defined envelope. Thus it is amenable to demodulation by an envelope detector. Some sort of decision-making circuitry is necessary for detecting the message. The signal, which is a binary sequence is recovered by using a correlator and decision making circuitry.
Matlab Program for Frequency shift keying
program for Quadrature Amplitude Modulation
Matlab program for phase shift keying
program for Quadrature Phase shift keying-Generation of ASK:
Amplitude shift keying - ASK - in the context of digital communication is a modulation process which imparts to a sinusoid two or more discrete amplitude levels 1. These are related to the number of levels adopted by the digital message. For a binary message sequence, there are two levels one of which is typically zero. Thus the modulated waveform consists of bursts of a sinusoid.
Demodulation of ASK:
ASK signal has a well defined envelope. Thus it is amenable to demodulation by an envelope detector. Some sort of decision-making circuitry is necessary for detecting the message. The signal, which is a binary sequence is recovered by using a correlator and decision making circuitry.
Matlab Program for Frequency shift keying
program for Quadrature Amplitude Modulation
Matlab program for phase shift keying
program for Quadrature Phase shift keying
Platform: |
Size: 3072 |
Author:punitha sp |
Hits:
Description: QAM信号的生成程序（正交振幅调制，其幅度和相位同时变化）- QAM Signal generation Quadrature amplitude modulation, changes in the amplitude and phase at the same time Platform: |
Size: 1024 |
Author:knight |
Hits:
Description: tA scheme of format conversion optical 16-ary quadrature amplitude modulation (16QAM) toquadrature phase shift keying (QPSK) signal based on cascaded four-wave mixing (FWM) in semiconduc-tor optical amplifiers (SOAs) is proposed. Theoretical analysis and simulations of the format conversionscheme are conducted to validate the feasibility of the proposal. In this proposal, the phase conjugatedof 16QAM signal is generated after the first FWM process in an SOA, and then the QPSK signal is con-verted due to the second non-degenerate FWM (ND-FWM) process in another SOA. The performance andthe optimal design of the 10 Gbit/s format conversion system under various key parameters of SOAs are uated and discussed. Simulation results present useful to enable interconnection between backbonenetwork and access network.-tA scheme of format conversion optical 16-ary quadrature amplitude modulation (16QAM) toquadrature phase shift keying (QPSK) signal based on cascaded four-wave mixing (FWM) in semiconduc-tor optical amplifiers (SOAs) is proposed. Theoretical analysis and simulations of the format conversionscheme are conducted to validate the feasibility of the proposal. In this proposal, the phase conjugatedof 16QAM signal is generated after the first FWM process in an SOA, and then the QPSK signal is con-verted due to the second non-degenerate FWM (ND-FWM) process in another SOA. The performance andthe optimal design of the 10 Gbit/s format conversion system under various key parameters of SOAs are uated and discussed. Simulation results present useful to enable interconnection between backbonenetwork and access network. Platform: |
Size: 1298432 |
Author:yangs |
Hits:
Description: Introduction
This section builds an example step-by-step to give you a first look at the Communications System Toolbox™ software. This section also shows how Communications System Toolbox functionalities build upon the computational and visualization tools in the underlying MATLAB® environment.
Modulate a Random Signal
This example shows how to process a binary data stream using a communication system that consists of a baseband modulator, channel, and demodulator. The system s bit error rate (BER) is computed and the transmitted and received signals are displayed in a constellation diagram.
The following table summarizes the basic operations used, along with relevant Communications System Toolbox and MATLAB functions. The example uses baseband 16-QAM (quadrature amplitude modulation) as the modulation scheme and AWGN (additive white Gaussian noise) as the channel model.-Introduction
This section builds an example step-by-step to give you a first look at the Communications System Toolbox™ software. This section also shows how Communications System Toolbox functionalities build upon the computational and visualization tools in the underlying MATLAB® environment.
Modulate a Random Signal
This example shows how to process a binary data stream using a communication system that consists of a baseband modulator, channel, and demodulator. The system s bit error rate (BER) is computed and the transmitted and received signals are displayed in a constellation diagram.
The following table summarizes the basic operations used, along with relevant Communications System Toolbox and MATLAB functions. The example uses baseband 16-QAM (quadrature amplitude modulation) as the modulation scheme and AWGN (additive white Gaussian noise) as the channel model. Platform: |
Size: 1024 |
Author:Thanh CRuise |
Hits:
Description: Introduction
This section builds an example step-by-step to give you a first look at the Communications System Toolbox™ software. This section also shows how Communications System Toolbox functionalities build upon the computational and visualization tools in the underlying MATLAB® environment.
Modulate a Random Signal
This example shows how to process a binary data stream using a communication system that consists of a baseband modulator, channel, and demodulator. The system s bit error rate (BER) is computed and the transmitted and received signals are displayed in a constellation diagram.
The following table summarizes the basic operations used, along with relevant Communications System Toolbox and MATLAB functions. The example uses baseband 16-QAM (quadrature amplitude modulation) as the modulation scheme and AWGN (additive white Gaussian noise) as the channel model.-Introduction
This section builds an example step-by-step to give you a first look at the Communications System Toolbox™ software. This section also shows how Communications System Toolbox functionalities build upon the computational and visualization tools in the underlying MATLAB® environment.
Modulate a Random Signal
This example shows how to process a binary data stream using a communication system that consists of a baseband modulator, channel, and demodulator. The system s bit error rate (BER) is computed and the transmitted and received signals are displayed in a constellation diagram.
The following table summarizes the basic operations used, along with relevant Communications System Toolbox and MATLAB functions. The example uses baseband 16-QAM (quadrature amplitude modulation) as the modulation scheme and AWGN (additive white Gaussian noise) as the channel model. Platform: |
Size: 1024 |
Author:Thanh CRuise |
Hits:
Description: analog modulation techniques are:
Amplitude modulation (AM) (here the amplitude of the carrier signal is varied in accordance to the instan eous amplitude of the modulating signal)
Double-sideband modulation (DSB)
Double-sideband modulation with carrier (DSB-WC) (used on the AM radio broadcasting band)
Double-sideband suppressed-carrier transmission (DSB-SC)
Double-sideband reduced carrier transmission (DSB-RC)
Single-sideband modulation (SSB, or SSB-AM)
Single-sideband modulation with carrier (SSB-WC)
Single-sideband modulation suppressed carrier modulation (SSB-SC)
Vestigial sideband modulation (VSB, or VSB-AM)
Quadrature amplitude modulation (QAM)
-analog modulation techniques are:
Amplitude modulation (AM) (here the amplitude of the carrier signal is varied in accordance to the instantaneous amplitude of the modulating signal)
Double-sideband modulation (DSB)
Double-sideband modulation with carrier (DSB-WC) (used on the AM radio broadcasting band)
Double-sideband suppressed-carrier transmission (DSB-SC)
Double-sideband reduced carrier transmission (DSB-RC)
Single-sideband modulation (SSB, or SSB-AM)
Single-sideband modulation with carrier (SSB-WC)
Single-sideband modulation suppressed carrier modulation (SSB-SC)
Vestigial sideband modulation (VSB, or VSB-AM)
Quadrature amplitude modulation (QAM)
Platform: |
Size: 96256 |
Author:mojtaba |
Hits:
Description: frequency division multiplexing (OFDM) is used extensively in broadband wired and wireless communication systems because it is an effective solution to intersymbol interference (ISI) caused by a dispersive channel. This becomes increasingly important as data rates increase to the point where, when conventional serial modulation schemes like quadrature amplitude modulation (QAM) or NRZ are used, the received signal at any time depends on multiple transmitted symbols. In this case the complexity of equalization in serial schemes which use time domain equalization rises rapidly. In contrast, the complexity of OFDM, and of systems using serial modulation and frequency domain equalization, scale well as data rates and dispersion increase. [1]–[3]. A second major advantage of OFDM is that it transfers the complexity of transmitters and receivers the analog to the digital domain-frequency division multiplexing (OFDM) is used extensively in broadband wired and wireless communication systems because it is an effective solution to intersymbol interference (ISI) caused by a dispersive channel. This becomes increasingly important as data rates increase to the point where, when conventional serial modulation schemes like quadrature amplitude modulation (QAM) or NRZ are used, the received signal at any time depends on multiple transmitted symbols. In this case the complexity of equalization in serial schemes which use time domain equalization rises rapidly. In contrast, the complexity of OFDM, and of systems using serial modulation and frequency domain equalization, scale well as data rates and dispersion increase. [1]–[3]. A second major advantage of OFDM is that it transfers the complexity of transmitters and receivers the analog to the digital domain Platform: |
Size: 415744 |
Author:kartick |
Hits:
Search - signal Quadrature Amplitude Modulation