Frequency-Domain Spatial Modulation

Abstract

Spatial modulation (SM) is a multiple-input multiple-output (MIMO) technique, which was introduced for wireless communication systems in which the number of transmit RF chains is smaller than the number of antennas. The basic principle in this technique is to select transmit antennas using information bits and transmit data symbols from these antennas. Obviously, SM involves symbol-rate antenna switching, which leads to serious problems and degradations in practice due to the non-rectangular pulse shaping used. Combining SM with orthogonal frequency-division multiplexing (OFDM) leads to what we call Frequency-Domain SM (FDSM). This technique avoids antenna switching and eliminates the related problems. However, the number of RF chains required to implement it is no longer smaller than the number of transmit antennas, but the power requirements are reduced as compared to conventional MIMO/OFDM. In this paper, we investigate the requirements in terms of high-power amplifiers and we introduce a Balanced FDSM scheme, which further reduces these requirements.