A Novel Spectrum Encoding MIMO Communication System

Abstract

This paper presents a novel spectrum/wavelet encoding MIMO system. To avoid spectrally crowded regions, the system synthesizes the fundamental modulation waveform in the spectral/wavelet domain rather than in the time domain at both the transmitter and the receiver. Based on the Vertical Bell Laboratories Layered Space-Time (V-BLAST) architecture, we propose two enhanced MIMO architectures, which utilize two different schemes: spectrum domain encoding (SDE) and wavelet domain encoding (WDE) respectively. Both approaches offer better bit error rate (BER) performance compared to other conventional interference mitigation techniques that process the signal at the receiver only. However, the SDE based MIMO system is not able to deal with non-stationary interference, and the WDE based MIMO system could overcome this shortcoming but slightly degrades the performance under stationary interference. The analysis shows that under interference the channel capacity of the proposed MIMO system is higher than that of conventional systems. Our simulation results also indicate that the system BER performance is significantly improved with little or no interference to the spectral crowed regions. By the virtue of its flexibility and adaptivity, the proposed system is one potential candidate for a reliable communication system or the cognitive radio technology.