Joint CFO and Channel Estimation for OFDM-Based Two-Way Relay Networks
Joint CFO and Channel Estimation for OFDM-Based Two-Way Relay Networks
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DOI：
10.1109/twc.2010.120310.091615
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发表时间：
2011-02
影响因子：
10.4
通讯作者：
Gongpu Wang;Feifei Gao;Yik-Chung Wu;C. Tellambura
中科院分区：
文献类型：
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作者：
Gongpu Wang;Feifei Gao;Yik-Chung Wu;C. Tellambura
针对由两个源终端和一个放大转发（AF）中继组成的双向中继网络（TWRN），开发了载波频率偏移（CFO）和信道的联合估计。终端采用正交频分复用（OFDM）。提出了新的零填充（ZP）和循环前缀（CP）传输协议，既保持了载波正交性，又保证了较低的估计和检测复杂度。这两种协议都存在相同的估计问题，该问题可以用基于零的最小二乘（LS）算法来解决，并且在块长度较大时性能相同。我们通过证明LS估计器在高信噪比（SNR）下的无偏性和推导均方误差（MSE）的封闭形式表达式，给出了详细的性能分析。仿真结果证实了我们的发现。
Joint estimation of the carrier frequency offset (CFO) and the channel is developed for a two-way relay network (TWRN) that comprises two source terminals and an amplify-and-forward (AF) relay. The terminals use orthogonal frequency division multiplexing (OFDM). New zero-padding (ZP) and cyclic-prefix (CP) transmission protocols, which maintain the carrier orthogonality and ensure low estimation and detection complexity, are proposed. Both protocols lead to the same estimation problem which can be solved by the nulling-based least square (LS) algorithm and perform identically when the block length is large. We present detailed performance analysis by proving the unbiasedness of the LS estimators at high signal-to-noise ratio (SNR) and by deriving the closed-form expression of the mean-square-error (MSE). Simulation results are provided to corroborate our findings.