Detection and Performance Analysis of Near-Field Space Shift Keying

This letter studies the effect of near field (NF) propagation on the detection of space shift keying signals when the mobile user either operates in the NF all the time or moves from the far field (FF) to the NF during operation. The performances of the maximum likelihood detectors in the NF, FF and mismatched cases are compared and also analyzed using the union bounds. Numerical results show that the NF case slightly outperforms the FF case due to the extra difference in the large-scale fading and that the mismatched case suffers from significant performance loss due to the change of propagation environment. This performance loss increases when the number of transmitting antennas, the number of receiving antennas or the signal-to-noise ratio increase. More importantly, the user location has a large impact in the mismatched case.