摘要
该文设计了一种联合判决-反馈均衡的单载波频域均衡(SC-FDE)系统,该系统用固定波形的短pn序列取代常规SC-FDE系统中的循环前缀(CP),并以多个短pn序列组成的长PN序列作信道训练从而解决快变信道的初始估计和跟踪问题。针对该系统,一种在时域内对接收的多个训练序列进行平均,然后提出了在频域对信道信息进行估计的信道训练算法,该算法与传统SC-FDE系统相比,其计算复杂度较低。另外,提出了一种增加纵向校验的LDPC码用于该系统中降低信噪比门限,提高系统的整体性能。仿真结果表明在多径衰落信道中,此系统可获得较为理想的结果。
This paper introduces a single-carrier system with hybrid time-frequency domain Decision Feedback Equalization (DFE), in which the short pn (Pseudo-Noise) sequence with fixed waveform replaces the cyclic prefix (CP) in the conventional Single Carrier systems with Frequency Domain Equalization (SC-FDE), and the long PN sequences composed of several short pn sequences are employed as the channel training sequences to complete the initial estimation and tracking for fast-varying channel. In this system, the received training sequences are averaged in time domain and then the channel is estimated in frequency domain. In comparison with traditional SC-FDE systems, its complexity is lower. Furthermore, an approach of adding sum-check blocks to original Low-Density Parity-Check (LDPC) blocks is presented, and the effective improvements of this system performance can be achieved. Finally, the simulation results show that this system works well over the fading channel.
出处
《电子与信息学报》
EI
CSCD
北大核心
2008年第4期817-821,共5页
Journal of Electronics & Information Technology
关键词
单载波系统
LDPC码
频域均衡
判决-反馈均衡
循环前缀
Single carrier system
Low-Density Parity-Check (LDPC) codes
Frequency Domain Equalization (FDE)
Decision Feedback Equalization (DFE)
Cyclic Prefix (CP)