面向空间复用系统的抗干扰空频自适应均衡方法

An Adaptive Space-Frequency Anti-Interference Equalization Method for Spatial Multiplexing Systems

针对多天线空间复用系统中各天线发射信号互相干扰,进而降低系统通信质量的问题,提出了一种抗干扰空频自适应均衡方法。首先,在发射端将待发射信号以空间复用的形式发送至接收端;然后,基于最小均方误差(MMSE)准则,利用各接收天线接收到的导频信息进行自适应均衡器的参数估计;最后,利用估计所得参数,进一步通过迭代优化的方法实现数据检测。在参数估计的过程中,通过引入相关移位矢量集的方法对抗多天线发射信号间的相互干扰,从而降低这种内部干扰对系统性能的影响。与传统针对空间复用结构的自适应空时、空频均衡方法相比,所提自适应均衡方法在性能上有显著提升。仿真结果表明:相较传统针对空间复用结构的自适应空时、空频均衡方法,在误比特率为10-5时,所提自适应均衡方法有约2.5 dB的性能提升;在外界干扰影响下,传统针对空间复用结构的自适应空时、空频均衡方法具有明显误比特率平台,而所提自适应均衡方法表现出了更强的抗干扰能力,没有明显的性能平台。

Aiming at the problem that the mutual interferences among different antennas from the desired user in the spatial multiplexing system reduce the communication quality,a new adaptive space-frequency anti-interference equalization method is proposed.Firstly,signals to be transmitted are sent to the receive antennas in the form of spatial multiplexing at the transmitter;Then,the adaptive equalizer is first designed based on the minimum mean square error(MMSE)criterion by exploiting the pilot signal received by each receive antenna;Finally,parameters estimated from the designed adaptive equalizer are used to detect the data through iterative optimization.In the process of parameter estimation,the proposed method makes use of the mutual interferences among different antennas from the desired user rather than attempts to completely remove them,thereby reducing its impact on system performance.Simulation results show that the proposed method can achieve significant gain in performance over the traditional adaptive space-time or space-frequency equalization methods.When the bit error rate is 10-5,the proposed method achieves around 2.5 dB performance gain as compared with the existing competitors.Moreover,in the presence of interference,the proposed method also exhibits much stronger anti-interference capability compared with existing schemes,and there is no obvious performance platform.