用于旋转映射信号的多天线联合Turbo均衡算法

旋转映射信号将编码比特旋转移位后映射为符号,同时采用了隐性交织、加扰等技术,具有交织复杂度低、信道效率高等特点,是一种典型且使用较为广泛的短波通信信号.针对第三方接收条件下,频率选择性衰落造成该类信号难以有效接收的问题,推导了该类信号的软符号解映射、映射方法,提出了一种针对该类信号的多天线联合Turbo均衡算法,实现了软信息在均衡与译码之间的迭代交换.典型短波信道下的仿真结果表明,迭代4次后的两天线联合Turbo均衡在10-5误码率时相对两天线硬判决译码提供了约4 dB的增益,相对两天线软判决译码提供了约1 dB的增益,在10-4误码率时相对单天线Turbo均衡提供了约5.5 dB的增益.

A multi-antenna Turbo equalization algorithm for rotation-mapping signals

The characteristic of rotation mapping signal is that the encoded bit stream is mapped onto sym-bols after several times of rotation. Implicit interleaving and peudo-noise( PN) spreading are also used in this signal, so it has high channel efficiency and is widely used in high frequency ( HF) communication. For effective receiving of this signal in frequency selective fading channel by a third-party receiver, a method of soft symbol demapping and mapping is deduced and a multi-antenna Turbo equalization algo-rithm is proposed, so as to exchange soft information between the equalizers and decoder. Simulation in HF channel shows that the proposed algorithm achieves about 4 dB improvement compared with the hard sym-bol decision algorithm and about 1 dB improvement compared with the soft symbol decision algorithm when the bit error rate(BER) is 10-5 and about 5. 5 dB improvement compared with the single-antenna Turbo e-qualization when BER is 10-4 under the condition of two antennas and 4 iterations.