为了提高频谱资源利用率, 3GPP长期演进(LTE)在组网时通常采用同频组网的方式, 但相邻小区之间因此会产生同频干扰问题。同频干扰加大了小区检测的难度, 特别是当2个小区使用相同的主同步信号(PSS)时。在这种情况下, 由于很难直接通过PSS估计出辅同步信号(SSS)所在位置的信道频域响应(CFR), 因此极大降低了弱信号小区的检测成功率。为了解决该问题, 本文提出一种同频干扰下的LTE小区检测的方法。所提方法首先对小区接收信号进行合理建模, 通过求解方程组的方式估计出强信号小区的CFR, 然后进行干扰抵消, 之后进行弱信号小区的检测。仿真结果表明, 所提方法能大幅提高弱信号小区的检测成功率, 当信噪比(SNR)等于10 dB时, 有70%的检测成功率；SNR等于20 dB时, 有90%以上的成功率, 相较普通小区检测法的50%有显著进步。

To improve the spectral efficiency, 3rd Generation Partnership Project(3GPP) Long Term Evolution(LTE) usually adopts frequency reuse-1 system, which leads to co-channel interference among neighbor cells. Co-channel interference increases the difficulty of cell detection, especially when two neighbor cells use the same Primary Synchronization Signal(PSS). In such cases, since it is difficult to obtain the channel frequency response(CFR) for the Secondary Synchronization Signal(SSS) by directly using the PSS, the detection rate for the cell with weak signal will significantly degrade. To address the above issue, this paper proposes a cell detection algorithm for the LTE system with co-channel interference. The proposed method first presents a reasonable model for the received signals, and then estimates the CFR of the cell with strong signal by solving the equations. After that, the interference is cancelled and the cell with weak signal is detected. Simulation results show that the proposed algorithm can significantly improve the detection rate of the cell with weak signal. Even when Signal-Noise Ratio(SNR）is 10 dB, the detection rate of the proposed algorithm can achieve 70%. When SNR is 20 dB, the detection rate can be above 90%, which significantly outperforms the typical cell detection algorithm whose detection rate is only 50%.