Impact of antenna spacing on Differential Spatial Modulation and Spatial Modulation for 5G-Based Compact Wireless Devices

Abstract

In this article, the bit error rate(BER) analysis of channel correlation on differential spatial modulation(DSM) and spatial modulation(SM) have been studied. There is a vital role of channel correlation in differential spatial modulation(DSM) and spatial modulation(SM), as it is alternative of spatial multiplexing especially for higher spectral efficiency. We have considered three transmit and two receive antenna deployed in Rayleigh fading channel in which only one active transmit antenna at transmitter side. The reason behind the study of differential spatial modulation(DSM) is, it do not require channel state information at transmitter as well as receiver which is quite intuitive for practical scenario of wireless communication. For this investigation, we have considered diverse transmit antenna spacing values of d <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</inf> = 0.1, 0.2 and 0.4 hold up d <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 0.1 and diverse receive antenna spacing values of d <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 0.1, 0.2 and 0.4 hold up d <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</inf> = 0.1. The investigation shows that the BER of DSM with QPSK is 3dB improved compare to SM with BPSK which implies that DSM-BER improved with one step higher modulation scheme. From the simulation result, the effect of antenna spacing or spatial correlation is more on the side of the receiving antenna compared to the side of the transmitting antenna. Moreover, antenna spacing or spatial correlation has more effect in spatial modulation than differential spatial modulation.