Sample indexed spatial orthogonal frequency division multiplexing
Sample indexed spatial orthogonal frequency division multiplexing作者机构:Department of Electrical and Computer Engineering Boston University
出 版 物:《Chinese Optics Letters》 (中国光学快报(英文版))
年 卷 期:2014年第12卷第9期
页 面:10-14页
核心收录:
学科分类:0808[工学-电气工程] 0809[工学-电子科学与技术(可授工学、理学学位)] 08[工学] 0805[工学-材料科学与工程(可授工学、理学学位)] 0803[工学-光学工程] 0702[理学-物理学]
主 题:OFDM SIS DCO Sample indexed spatial orthogonal frequency division multiplexing
摘 要:Optical spatial modulation (OSM) is a multiple-transmitter technique that can provide higher data rates with low system complexity as compared with single-input single-output systems. Orthogonal frequency division multiplexing (OFDM) is widely implemented to achieve better spectral efficiency in wireless channels. Asymmetrically clipped optical OFDM (O-OFDM) and DC-biased O-OFDM are two well-known O-OFDM techniques suitable for intensity-modulation direct-detection optical systems. In this work, sample indexed spatial OFDM (SIS-OFDM) is proposed to combine OSM and O-OFDM in a novel way and achieve significant per- formance gain. By assigning time-domain samples of the O-OFDM transmit symbol to different transmitters, SIS-OFDM achieves much better spectral efficiency and reduces computational complexity at the transmitter as compared with previous work that combines OSM with O-OFDM in the frequency domain. We also consider the impact of optical source biasing on overall performance, and the relative performance of imaging receiver (ImR) versus non-imaging receiver (NImR) design for our proposed SIS-OFDM technique. Results indicate that for an Ntx x Nrx multiple-input multiple-output configuration where Nix = N = 4, SIS-OFDM using ImR can achieve up to 135 dB of signal-to-noise ratio gain over comparable system using a NImR. Also, using Nc number of O-OFDM subcarriers provides up to Nsc × log2(Ntx) additional bits per symbol of spectral efficiency over technioues that combine OSM and O-OFDM in the freollencv domain.