Abstract
Conventional diversity techniques like maximal ratio combining (MRC) and maximal ratio transmission (MRT), or space-time coding techniques like space-time block coding (STBC) and space-time line coding (STLC), are widely used to fully exploit the diversity gain of the multiple antennas in MIMO networks. The choice of these techniques depends on the availability of the channel state information (CSI) at the transmitter or receiver, as well as the coding/decoding complexities. While STBC technique requires the full CSI at the receiver for symbol detection, STLC technique looses this strict requirement. Since, the data payload for the CSI requirement and the processing complexity would increase linearly with the increasing number of antenna elements, STLC scheme promises to provide substantial advantages, especially in case of massive number of antennas. However, the performance of STLC degrades drastically due to the practical impairments of the communication environment, such as channel estimation error (CEE) or time-selectivity of the fading channels based on the mobility of scatterers within the environment. This paper investigates the massive multiple-input multiple-output (MIMO) wireless communications schemes-STLC scheme by incorporating the orthogonal frequency-division multiplexing (OFDM) technique in the presence of system and channel impairments. In order to examine the average bit error rate (BER) performances for different system configurations and channel parameters, Monte Carlo simulations have been performed for both the ideal and imperfect conditions. Simulation results indicate that despite suffering from the practical imperfections drastically, STLC-OFDM scheme might overcome these deteriorations by utilizing massive antenna elements (i.e., massive MIMO).