Joint channel estimation and time-frequency synchronization for uplink TDS-OFDMA systems
Joint channel estimation and time-frequency synchronization for uplink TDS-OFDMA systems
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DOI：
10.1109/tce.2010.5505961
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发表时间：
2010-05
影响因子：
4.3
通讯作者：
L. Dai;Zhaocheng Wang;Jun Wang;Zhixing Yang
中科院分区：
文献类型：
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作者：
L. Dai;Zhaocheng Wang;Jun Wang;Zhixing Yang
时域同步正交频分复用（TDS-OFDM）技术是国家数字电视地面广播（DTTB）标准的关键技术之一，用于下行广播传输场景。基于TDS-OFDM，最近已经提出了称为TDS-OFDMA的上行链路多址方案。TDSOFDMA系统假设完美的定时和频率同步，这两者在上行链路传输中很难实现，其中每个用户的信号的特征在于用户特定的定时和频率误差。利用时域恒幅零自相关（CAZAC）训练序列和“时空间二维帧结构”，提出了一种适用于TDS-OFDMA的联合信道估计和时频同步方案。信道估计具有最小均方误差（MSE），定时同步准确，频率同步误差可达到克拉美-罗下界（CRLB）。联合算法仅依赖于时域循环相关，实现了低复杂度。仿真结果表明，在加性白色高斯噪声（AWGN）和多径信道下，所提出的联合方法的性能。
As one of the key technologies of the Chinese national digital television terrestrial broadcasting (DTTB) standard, time domain synchronous OFDM (TDS-OFDM) is used in the downlink broadcasting transmission scenarios. Based on TDS-OFDM, the uplink multiple access scheme called TDS-OFDMA has been recently proposed. The TDSOFDMA system assumes perfect timing and frequency synchronization, both of which are difficult to be achieved in the uplink transmission where each user's signal is characterized by the user-specific timing and frequency errors. By utilizing the time-domain constant amplitude zero autocorrelation (CAZAC) training sequence and the "timespace two-dimensional frame structure", this paper proposes a joint channel estimation and time-frequency synchronization scheme for TDS-OFDMA. The channel estimation has the minimum mean square error (MSE), the timing synchronization is accurate and the frequency synchronization error can reach the Cramer-Rao lower bound (CRLB). The joint algorithm only relies on the time-domain circular correlation, thus low complexity is achieved. Simulation results demonstrate the performance of the proposed joint method under both additive white Gaussian noise (AWGN) and multi-path channels.