Partial intersection sphere decoding with weighted voting for sparse rotated V-OFDM systems

• Published in: Science China. Information sciences 2018-02, Vol.61 (2), p.73-85, Article 022304
• Main Authors: Feng, Qi, Xia, Xiang-Gen, Zhang, Naitong
• Format: Article
• Language: English
• Subjects: Antennas; Broadband; Carrier frequencies; Complexity; Computer Science; Engineering; Fourier transforms; Information Systems and Communication Service; Matrix algebra; Maximum likelihood decoding; Maximum likelihood estimation; Orthogonal Frequency Division Multiplexing; Receivers & amplifiers; Research Paper; Signal to noise ratio; Transmitters; Voting; 旋转矩阵; 一般系统; 译码方法; 投票系统; 加权; 接收装置; OFDM; 复杂性
• ISSN: 1674-733X; 1869-1919
• DOI: 10.1007/s11432-016-9053-3

Vector orthogonal frequency division multiplexing（V-OFDM） is a general system that builds a bridge between OFDM and single-carrier frequency domain equalization in terms of intersymbol interference level and receiver complexity. In this paper, we focus on a rotated V-OFDM system over a broadband sparse channel owing to its large time delay spread and fewer nonzero taps. In order to collect the multipath diversity,a simple rotation matrix is designed, independent of the number of subchannels at the transmitter. For the rotated V-OFDM receiver, a partial intersection sphere decoding with weighted voting method is proposed by exploiting the sparse nature of the multipath channel. The proposed receiver chooses the transmitted vector from the set with the maximum likelihood estimation generated using the partial intersection sphere decoding method. For an extreme case, such as when a candidate set is empty, which usually occurs at a low signal-to-noise ratio（SNR）, an efficient weighted voting system is used to estimate the transmitted vectors symbol-by-symbol. Simulation results indicate that the proposed receiver improves the symbol error rate performance with reduced complexity, especially for low SNR scenarios.