BOMA and OFDM/OQAM modulation for a radio-over-fiber system with enhanced spectral efficiency

作者:Chen, Xiaoman; Liu, Chang; Nian, Laixia*; Cheng, Mengfan; Fu, Songnian; Tang, Ming; Liu, Deming; Deng, Lei
来源:Optics Letters, 2018, 43(20): 4859-4862.
DOI:10.1364/OL.43.004859

摘要

A novel radio-over-fiber system with enhanced spectral efficiency is proposed by using a building-block-sparse-constellation-based orthogonal multiple access (BOMA) technique, and orthogonal frequency-division multiplexing with offset quadrature amplitude modulation (OFDM/OQAM) technique. With the help of BOMA, a user with good signal-to-noise ratio (SNR) can use the frequency band of a user with poor SNR to transmit extra information by sharing the same well-designed constellation. Moreover, the cycle prefix in OFDM is no longer required due to the properly designed prototype filters in OFDM/OQAM, contributing to maximum spectral efficiency (SE). To optimize transmission performance, four types of sparse constellations with different Euclidean distances between constellation points are designed. In our experiment, BOMA-OFDM/OQAM signals with a total net rate of 1.84 Gb/s and average SE of 4.6 bit/s/Hz are successfully transmitted over 25.2 km standard single-mode fiber for two users with wireless distances of 0.8 m and 0.3 m, respectively. Experimental results show that SE is increased by 37.7% compared with the traditional orthogonal frequency-division multiple access technique.