该文提出了在多径衰落信道环境下，宽带数字电视地面广播BDB-T系统中符号定时恢复的改进新算法，导出了计算公式井设计了相应的FPGA硬件电路，计算机仿真驶在高清晰度数字电视功能样机上的调试证明了改进算法的优良性能。

该文深入研究了OFDM系统中基于查询表LUT方法的HPA数字预失真技术。针对传统LUT方法收敛速度非常慢的不足，有关文献提出了相应的改进措施。该文从误码率BER，功率谱密度PSD和算法收敛速度几个方面进行了算法性能的仿真比较分析，指出以上算法存在的不足，并提出了新的改进方法，仿真及分析结果表明了该文提出改进方法在性能上的优越性。

In this paper we focus our research on the symbol timing synchronization technique in COFDM systems. A new method utilizing pilots to do coarse symbol timing is proposed. It overcomes the problem of fluctuation of the estimated symbol start position with cyclic prefix correlation method. The symbol timing error with the proposed method is within only 10 samples. Different from the algorithms in [1]–[3], we utilize the known pilot information to estimate the residual symbol timing offset with low system complexity. This paper also proposes a new control model for the sampling clock adjustment, different from the phase-locked loop (PLL) [4], [5] or delay-locked loop (DLL) [2] method. The simulation and correspondent Field Programmable Gate Array (FPGA) circuit through test in HDTV prototype in Team of Engineering Expert Group (TEEG) proves its feasibility and availability. The proposed method is also suitable for burst mode transmission systems such as Wireless Local Area Network (WLAN) and Fixed-Broadband Wireless Access (F-BWA).

The latest research works on the synchronization scheme for either continuous transmission mode or burst packet transmission mode for the wireless OFDM communications are overviewed in this paper. The typical algorithms dealing with the symbol timing synchronization, the carrier frequency synchronization as well as the sampling clock synchronization are briefly introduced and analyzed. Three improved methods for the fine symbol timing synchronization in frequency domain are also proposed, with several key issues on the synchronization for the OFDM systems discussed.

In this paper, we focus on the Look-up Table (LUT) technique for the compensation of HPA nonlinear distortion. An improved LUT method is proposed with better performance compared with conventional LUT technique in terms of convergence speeds, BER and total degradation (TD). It can get over 8 dB gain in out-of-band spectrum re-growth suppression and about 0.3 dB BER performance gain than conventional LUT technique with the same iteration times. Also, we propose an actual application of HPA with pre-distorter in OFDM transmitter.