一种水声MC-CDMA多用户信道估计仿真研究

摘要

研究水声信道优化估计问题,在资源受限的水声环境下,多载波码分多址(MC-CDMA)上行系统信道,由于受到各种干扰,怎样获取多用户的信道准确信息是一个难题.为此提出了一种采用DFT的上行信道估计算法,可以很好的解决了上述问题.算法是在频域上构造不同的导频信号,在时域上估计用户的冲激响应从而得到其信道传输函数.采用改进方案的水声MC-CDMA系统在获得有效频谱效率和分集增益的同时,还能获得很好的误码率性能.首先利用DFT信道估计算法的性能,进行仿真.结果表明,DFT及改进算法较传统的LS信道估计算法,可以使水声系统性能有明显的提高,降低多用户干扰的影响,为水声多用户信道优化估计提供了依据.%A large amount of uplink channel information is difficult to estimate for MC-CDMA underwater acoustic communication (UWAC) uplink system. In this paper, an uplink channel estimation algorithm was proposed to solve this problem with spectral efficiency, as well as the frequency diversity without loss of much BER performance for MC -CDMA UWAC system. The basic idea is constructing different pilots in frequency domain and estimating channel impulse response in time domain. The performance of the algorithm was analyzed. Matlab simulation results also indicate that the uplink channel estimation algorithm can obviously improve the system performance compared with the one based on LS norm, with the reduction of the multiuser interference.