正交空时编码连续相位调制系统的信道估计算法

针对准静态瑞利衰落信道中突发模式的正交空时编码连续相位调制（OSTC-CPM）,利用双发多收空时编码连续相位调制系统的波形正交特性,提出了一种基于数据辅助的信道估计算法.接收天线将得到的信号同步地乘上每一发射天线对应的训练序列,然后延迟一码元相加并除以该训练序列能量,估计得到相应的信道衰落系数.理论分析结果表明,该算法的对数估计方差随比特信噪比的增加而线性减小.对不同训练序列长度、过采样倍数和成形滤波器进行仿真,结果表明在准静态瑞利衰落信道中,估计性能与理论分析结果吻合,系统的误比特性能与理想情况相差不到0.2 dB.该算法适合OSTC-CPM系统在准静态衰落信道条件下的信道估计.

Channel estimation algorithm for orthogonal space-time coded continuous phase modulation systems

A data-aided channel estimation algorithm was proposed for a burst-mode orthogonal space-time coded continuous phase modulation(OSTC-CPM) system over quasi-static Rayleigh fading channels.This algorithm mainly uses the waveform orthogonality of space-time coded modulation systems with two transmit antennas and multiple receive antennas.Each receive antenna multiplies the received signal by the known training sequence which corresponding to one of the two transmit antennas;then the product is delayed for one symbol interval,and added together with the current signal;finally,the fading coefficient of the corresponding channel can be obtained by dividing the energy of the training sequence.Analytical variance of the estimation declines linearly by increasing the bit signalto-noise ratio for the proposed channel estimator.The effects of training sequence length,over-sampling ratio,and different pulse shaping filters were investigated.Simulation results matched the theoretical analysis.Compared with the known channel,the difference of bit error rate(BER) was less than 0.2 dB.Therefore,this algorithm is appropriate for OSTC-CPM systems over quasi-static Rayleigh fading channels.