摘要
在MIMO-OFDM水声通信系统中,由于信道间的相互干扰和水声信道严重时延扩展产生的频率选择性衰落,系统的通信误码率较高。针对这一问题,研究了空频编码的MIMO-OFDM通信,提出空频迭代信道估计与均衡(Spatial Frequency Iterative Channel Estimation and Equalization,SFICEE)方法。该方法通过载波间的空频正交性进行各收发阵元对的信道估计,并通过空频均衡获得符号初始估计,迭代更新信道估计,而后通过符号后验软信息反馈进行迭代空频软均衡。仿真结果表明,当误码率为10^(-3)时,文中所提出的SFICEE方法经过二次迭代与STBC方法相比具有4.8 d B的性能增益,相对于SFBC方法有2.8 d B的性能提升。当输入信噪比相同时,文中所提出方法的星座图更加收敛,可以更好地降低水下通信系统的误码率。
In MIMO-OFDM underwater acoustic communication system,mutual channel interference and frequency domain deep selectivity due to serious time delay in underwater acoustic channel lead to severe communication performance. We present SFICEE method for space frequency block coding MIMO-OFDM communication system. In this receiver algorithm,channel of each transceiver pair is estimated through taking advantage of the space frequency orthogonal characteristics. Then spatial frequency equalization is introduced to obtain initial symbol estimation.The symbol estimation is iteratively fedback to update the channel estimation and forwarded to spatial frequency soft equalization. Simulation and analysis show that,the proposed method gains about 4.8 d B as compared with STBC system and 2.8d B as compared with SFBC system after two iterations. And also this method gets great output signal to noise ratio（ R_（SN）） improvement,as can be seen from the convergence of constellation,and shows visible reduction in bit error ratio.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2016年第2期208-214,共7页
Journal of Northwestern Polytechnical University
基金
国家自然科学基金(61271415
61471298
61531015)
水下信息处理与控制国家重点实验室基金(9140C231002130C23085)
西北工业大学博士论文创新基金(CX201230)
西北工业大学基础研究基金-中央高校基本科研业务费专项基金(3102014JCQ01010)资助
关键词
水下通信
多输入多输出
正交频分复用
空频软均衡
迭代信道估计
algorithm
bit error rate
computer simulation
covariance matrix
convergence of numerical methods
estimation
flowcharting
iterative methods
least squares approximations
MIMO systems
orthogonal frequency division multiplexing
probability density function
random variables
signal to noise ratio
stochastic systems
time delay
underwater acoustics
vectors
MIMO channel
STBC（space time block coding）
SFICEE（spatial-frequency iterative channel estimation and equalization）
underwater acoustic communication
