关键词: 无线通信, 低信噪比, 前导检测, 分段相关, 分离多径接收, 现场可编程门阵列

Abstract:

Aiming at the contradiction between achievement of an enhanced detection performance by increasing the correlation length of the traditional time-domain direct correlation detection algorithm and its associated hardware implementation feasibility,a joint segment correlation and selective RAKE (JSC-SRAKE) preamble detection algorithm is proposed.Specifically,this algorithm reduces the complexity of hardware implementation by utilizing the concept of segment correlation,and employs RAKE receiving technology to collect the multipath signals to increase the detection signal energy.MATLAB simulation results show that both the probabilities of the missed detection and the false alarm of our proposal are less than 10^-4 when the SNR equals -17 dB.At the same time,the proposed algorithm increases the optional range of the optimal decision threshold after introducing the selective rake receiving algorithm,thereby reducing the impact of improper selection of the decision threshold on the detection performance.Compared with direct correlation detection and segment correlation detection,this algorithm has an improved gain in a low SNR region.Moreover,the resources consumed by the proposed algorithm are less than those by the existing algorithms.Although the algorithm increases the complexity,the gain it brings is huge.The algorithm proposed in this paper can achieve the optimal compromise between performance and cost while satisfying the detection performance.Finally,the algorithm is implemented by FPGA in the Single Carrier Interleaved Frequency Division Multiple Access (SC-IFDMA) system,with the results being consistent with those of MATLAB,indicating that the algorithm can be applied to multi-user communication systems with a similar low SNR.

Key words: wireless communication, low signal-to-noise ratio, preamble detection, segment correlation, RAKE receiver, FPGA implementation