基于FQPSK调制的盲均衡算法

摘要

针对低空航空信道多普勒、多径等衰落现象严重的问题,通过研究判决反馈盲均衡结构有效克服多径效应影响;超指数迭代算法收敛速度快,运算复杂度较低,修正的超指数算法还具有相位相关信息,可以纠正星座图相位旋转,减小稳态均方误差,加快收敛速度,降低误码率;结合FQPSK调制包络恒定,能量谱集中,抗多径的优点,提出一种基于FQPSK调制的超指数迭代盲均衡算法.仿真结果表明:在低空多径航空信道环境中,新算法可以很好地对多径信道进行跟踪并补偿,降低误码率,同基于QPSK调制的超指数迭代盲均衡算法相比,抗干扰性能明显加强.%For the Doppler aeronautical channels and multipath fading problem,a blind equalizer based on decision feedback structure is studied to efficiently combat the effects of multipath fading. Super-exponential iteration algorithm convergence speed,low computation complexity,the modified index algorithm also has the phase information,can correct the constellation diagram phase rotation, reduce the steady state mean square error,speed up the convergence speed,reduce the bit error rate. The modulation of FQPSK has the feature of constant envelope,concentrated energy spectrum and anti-multipath. This paper proposes a blind equalizer based on the modulation of FQPSK. The simulation results show that the proposed blind equalizer may not only track and compensate the multipath channels,and reduce the bit error rate. The new method has better advantage of anti-interference ability compared with the blind equalization based on the modulation of QPSK.