基于宽带突发单载波频域均衡传输的时域精细信道估计方法

Time-domain Fine Channel Estimation Based on Broadband Burst Single-carrier Frequency Domain Equalization Transmission

单载波频域均衡(SC-FDE)是宽带无线通信系统中一种具有竞争力的解决方案,获得了广泛的关注和研究。SC-FDE方案不仅抗多径能力出色、复杂度低,且具有比正交频分复用(OFDM)信号更低的峰均比值。在突发SCFDE系统中,接收机需要利用训练序列快速获取信道的特征信息,以避免解调性能损失。传统的基于训练序列的信道估计方法并不适合宽带猝发SC-FDE系统,难以兼顾估计准确性和复杂度。该文提出一种基于时域训练序列的精细信道估计方法。该方法利用时域PN序列得到信道参数的最大似然估计值,并利用信道稀疏的特征,根据信道噪声强度对信道估计值进行噪声抑制处理。仿真表明:与传统信道估计方法相比,该信道估计方法能取得更高的估计精度,且具有较低的实现复杂度。

Single Carrier-Frequency Domain Equalization（SC-FDE） is a competitive alternative for broadband wireless communication systems, which has attracted wide attention and extensive research. As an effective technical solution to cope with multipath effects, SC-FDE shows low complexity and has low signal peak to average power ratio compared with OFDM signals. In burst SC-FDE systems, channel information is required at the receivers to avoid the performance loss of demodulations. Traditional channel estimation methods based on training sequences are not very suitable for broadband burst SC-FDE system. In this paper, a fine channel estimation method based on the time-domain training sequence is proposed. Channel parameters are obtained with the aid of time domain PN sequence based on maximum likelihood criteria. Besides, the noise suppression process is performed for channel estimation values on account of the channel noise strength. Simulation results demonstrate that the proposed channel estimation method can significantly reduce the Bit Error Rate（BER） of signal reception while maintaining low realization complexity.