This paper describes the use of MATLAB Quadrature Amplitude modulation and demodulation of the simulation analysis, The simulation results show that the method is correct and feasible.
本文介绍了利用MATLAB进行正交振幅调制与解调的仿真分析，仿真结果验证了该方法的正确性和可行性。
The influence of random radio frequency error and quadrature demodulation error to interpulse stepped frequency radar is also studied in this paper.
本文还研究了脉间频率步进雷达中随机频率误差和正交解调误差对雷达系统的影响。
In chapter five, the base band signal process of CDMA base station simulator system is introduced, including channel coding and decoding, interleave and disinterleave, PN sequence generator, orthogonal spread spectrum and quadrature Spreading, scrambling code, power control, digital forming filter, the capture and track of PN code, dispreading and demodulation, etc. Some FPGA design graphic and waveform simulation of base band transmitter module is given and realization algorithm of base band receiver is discussed in detail.
第五章介绍了CDMA基站仿真系统的基带信号处理过程，包括信道编译码、交织与去交织、PN码发生器、正交扩频与四相扩频、扰码、功率控制、数字成形滤波器、PN码的捕获与跟踪、解扩与解调等，并给出了基带发射机模块的部分FPGA设计原理图和波形仿真，详细论述了基带接收机模块的实现算法。
Under the condition of narrowband constraint, a linear transforms is successfully adopted to modify quadrature demodulation error.
并在窄带约束条件下，成功使用一种线性变换方法进行正交解调误差的校正。
Based on polyphase filtering technology for digital quadrature transform, this paper presents a new algorithm for digital quadrature demodulation in SR through mathematical derivation.
文章基于多相滤波的数字正交变换技术，通过数学推导，提出了一种软件无线电中的数字化正交解调新算法。
We found the method had three primary errors: the error that is caused by speckle of laser interference system, the error that is caused by mixing in quadrature demodulation, and the error that is caused by the cosine fringe distortion in the structure light.
正交解调算法中混频频率所引入的误差，结构光中余弦条纹形变造成的误差。
Correction coefficients can be received based on statistic average when importing a test signal. Then quadrature demodulation errors are realized.
利用在接收机输入端加入测试信号，基于统计平均的思想求出所需要的校正系数，然后实现正交解调误差的校正。
The Influence of Quadrature Demodulation Errors on Broadband Beamforming
正交解调误差对宽带波束形成的影响
Implementation of Quadrature Demodulation and Complex Self-correlation Algorithm for Frequency Estimation on Ocean Current Measurement
正交解调及复自相关频率估计在海流测量中的应用
Research on Signal Processing Method Based on Quadrature Demodulation for Coriolis Mass Flowmeter
基于正交解调的科里奥利质量流量计信号处理方法研究
The Analysis and Correction of Quadrature Demodulation Errors of Ultra Wide Band Signal
超宽带信号正交解调误差的分析及校正
Then the results are analyzed and compared in order to design the applicable system, which are valuable to the system of quadrature amplitude modulation and demodulation.
通过对得到的仿真结果进行比较和分析，在理论上，得到合理设计QAM系统的方法.这些分析方法和得到的结论对工程中的QAM调制解调系统实现具有一定的价值。
Simulation and Performance Analysis on the System of Quadrature Amplitude Modulation and Demodulation Based on the Known Channels
基于已知特性信道的QAM系统的仿真和性能分析
Because of channel distortion and carrier frequency offset, both adaptive equalization and carrier recovery should be taken into account for high-order quadrature amplitude modulation (QAM) demodulation.
高阶QAM解调时，由于信道失真以及载波频偏相互影响，自适应均衡与载波恢复需要同时考虑。
Quadrature amplitude modulation (QAM) is one kind of high band efficiency, noise immunity modulation technology. Its modulation and demodulation system is simple. For these advantages, QAM is widely used in digital broadcasting and broadband access communication systems.
正交振幅调制（QAM）具有频带利用率高、抗噪声能力强、调制解调系统简单等优点，目前在数字广播、宽带接入等通信系统获得广泛应用。
An all-digital carrier phase acquisition scheme was presented to solve the problem of carrier phase recovery, which is specially critical and hard in the demodulation of trellis-coded quadrature amplitude modulation (TC-QAM).
针对TrellisCodedQAM（TC-QAM）解调系统中载波相位恢复难、收敛速度慢等问题，提出一种全数字方式实现的载波相位恢复方法。
The DPSK modem used the differential coherent detection to complete data demodulation, while, the QPSK modem used quadrature coherent demodulation based on carrier synchronization.
其中，DPSK系统采用差分相干解调的方式完成数据解调，而QPSK系统则采用相干解调方案，其难点在于载波同步的实现。
FFT/IFFT processor is the core data processing unit and is the key to realize data quadrature modulation and demodulation in OFDM system. The design of FFT/IFFT processor directly determines the performance of the OFDM system.
FFT/IFFT处理器是OFDM系统中数据处理的核心单元，是OFDM系统中数据正交调制和解调的关键，FFT/IFFT处理器的设计直接决定着OFDM系统的性能。
Under studying the function of a multi-mode polarization Synthetic Aperture Radar (SAR), the operation parameter, mixing, filtering method for digital IF receiver is presented based on Field Programmable Gate Array (FPGA). Digital quadrature demodulation for three bandwidth signal is realized.
针对一种多模式极化合成孔径雷达（SAR），给出了中频数字接收机工作参数选择，混频滤波方法，实现了三种带宽信号的数字正交解调。
The UWB impulse radar target-detection system including a power combination solid state pulse source, a UWB planar horn antenna array for transmitting and receiving, a quadrature demodulation receiver and a computer for controlling is designed, and its theory is presented.
文中设计了一套由功率合成的全固态脉冲发射机、超宽带平面喇叭收发天线阵、正交解调采样接收机、主控计算机四大部分组成的冲击体制雷达目标探测系统，介绍了系统的工作原理；