信道估计对于VRVP-MQAM系统的整体性能至关重要,论述了VRVP-MQAM方法在实际应用中遇到的问题,针对假定CSI已知的传统研究方法,该文通过采用MMSE算法进行信道估计,研究了MMSE估计误差对VRVP-MQAM方法的ASE性能影响,并在Rayleigh衰落信道...信道估计对于VRVP-MQAM系统的整体性能至关重要,论述了VRVP-MQAM方法在实际应用中遇到的问题,针对假定CSI已知的传统研究方法,该文通过采用MMSE算法进行信道估计,研究了MMSE估计误差对VRVP-MQAM方法的ASE性能影响,并在Rayleigh衰落信道下进行了仿真,仿真结果表明：与信道状态已知（ρ=1）相比,MMSE估计误差（ρ=0.9时）会产生1~3 d B左右的ASE性能差距;当平均SNR为20 d B时,MMSE算法下信道状态的平均频谱效率为0.3 bps/Hz,比理想信道状态的平均频谱效率低。因此,VRVP-MQAM方法的应用将会越来越广泛。展开更多
针对多阶相移键控信号(MPSK)和多阶正交调幅信号(MQAM)符号速率快速高精度估计问题,在分析信号特征和连续小波变换原理的基础上,提出了一种基于小波变换的MPSK/MQAM符号速率快速估计算法。该算法通过对中频信号进行归一化处理,消除幅度...针对多阶相移键控信号(MPSK)和多阶正交调幅信号(MQAM)符号速率快速高精度估计问题,在分析信号特征和连续小波变换原理的基础上,提出了一种基于小波变换的MPSK/MQAM符号速率快速估计算法。该算法通过对中频信号进行归一化处理,消除幅度变化的影响;利用固定尺度的小波变换将信号的相位跳变信息转换成其小波变换的幅度跳变信息,进而完成对符号速率的估计,并进行DSP实现验证。理论分析和仿真结果表明,在信噪比大于-10 d B条件下,算法达到较高的估计正确率和较小的估计均方误差,且DSP运行时间小于1 ms。展开更多
A novel wavelet network based adaptive equalizer (WNBAE) is presented and the structure and stochastic gradient learning algorithm is given. The proposed WNBAE has better performance than that of the conventional lin...A novel wavelet network based adaptive equalizer (WNBAE) is presented and the structure and stochastic gradient learning algorithm is given. The proposed WNBAE has better performance than that of the conventional linear transversal equalizer based on the LMS and the RLS algorithms, as well as that of the decision feedback equalizer based on the RLS algorithm, especially for MQAM digital communication reception systems over the nonlinear channels. In addition, it outperforms the BP neural network based adaptive equalizer slightly. However, it has a slow convergence rate and a high computational complexity. Several simulations are performed to evaluate the behavior of the WNBAE.展开更多
文摘信道估计对于VRVP-MQAM系统的整体性能至关重要,论述了VRVP-MQAM方法在实际应用中遇到的问题,针对假定CSI已知的传统研究方法,该文通过采用MMSE算法进行信道估计,研究了MMSE估计误差对VRVP-MQAM方法的ASE性能影响,并在Rayleigh衰落信道下进行了仿真,仿真结果表明：与信道状态已知（ρ=1）相比,MMSE估计误差（ρ=0.9时）会产生1~3 d B左右的ASE性能差距;当平均SNR为20 d B时,MMSE算法下信道状态的平均频谱效率为0.3 bps/Hz,比理想信道状态的平均频谱效率低。因此,VRVP-MQAM方法的应用将会越来越广泛。
文摘针对多阶相移键控信号(MPSK)和多阶正交调幅信号(MQAM)符号速率快速高精度估计问题,在分析信号特征和连续小波变换原理的基础上,提出了一种基于小波变换的MPSK/MQAM符号速率快速估计算法。该算法通过对中频信号进行归一化处理,消除幅度变化的影响;利用固定尺度的小波变换将信号的相位跳变信息转换成其小波变换的幅度跳变信息,进而完成对符号速率的估计,并进行DSP实现验证。理论分析和仿真结果表明,在信噪比大于-10 d B条件下,算法达到较高的估计正确率和较小的估计均方误差,且DSP运行时间小于1 ms。
文摘A novel wavelet network based adaptive equalizer (WNBAE) is presented and the structure and stochastic gradient learning algorithm is given. The proposed WNBAE has better performance than that of the conventional linear transversal equalizer based on the LMS and the RLS algorithms, as well as that of the decision feedback equalizer based on the RLS algorithm, especially for MQAM digital communication reception systems over the nonlinear channels. In addition, it outperforms the BP neural network based adaptive equalizer slightly. However, it has a slow convergence rate and a high computational complexity. Several simulations are performed to evaluate the behavior of the WNBAE.
