发射分集TDS-OFDM系统中迭代NR译码辅助的信道估计

为了改善信道估计的精度并提高时域同步正交频分复用(TDS-OFDM)系统在衰落信道下的性能,在发射分集TDS-OFDM系统中提出了一种迭代NR(Nordstrom-Robinson)译码辅助的信道估计方法。该方法利用对NR译码后的比特辅助指导信道估计,更新后的信道估计结果又重新辅助进行NR译码。完成迭代后,对NR译码结果进行帧间解交织,最后经过低密度奇偶校验(low-density parity-check,LDPC)译码输出最终的比特流。仿真结果表明:该方法应用于发射分集TDS-OFDM系统中在仅迭代1次的条件下即能有效改善信道估计的精度,获得显著的分集增益。

Iterative NR decoding aided channel estimation for TDS-OFDM systems with transmit diversity

An iterative Nordstrom-Robinson(NR) decoding aided channel estimation method is presented for time-domain synchronous orthogonal frequency division multiplexing(TDS-OFDM) systems with transmit diversity to improve the channel estimates and the performance of TDS-OFDM systems with fading channels.The NR decoded bits are used to perform the channel estimations,with the updated channel estimation results then utilized for the NR decoding.After several iterations,the NR decoded bits are inter-frame de-interleaved and LDPC decoded to obtain the final output bits.Simulations show that this method effectively improves the channel estimation accuracy in systems with transmit diversity after only one iteration to achieve significant diversity gain.