Performance and PAPR Analysis of Single-Carrier Massive MIMO Systems with Channel Imperfections

The performance of a single carrier system employing a large number of antennas is explored in this paper, considering the realizability in the millimeter-Wave (mmWave) range in 5G standardization. A significant disadvantage of Orthogonal Frequency division Multiplexing (OFDM) systems, which are currently being used in 4G LTE downlink, is its large peak-to-average power patio (PAPR). In addition, considering massive multiple-input-multiple-output (MIMO) scenario, implementing Inverse fast Fourier transform(IFFT)/fast Fourier transform(FFT) blocks per antenna branch makes the transceivers susceptible to higher complexity in implementation. A single carrier system has therefore the advantage of being relatively simple at the receiver side. However, due to the precoding needed in the downlink, the PAPR value increases with the number of channel taps. Performance of the system is investigated through simulations for single and multiuser cases with different large antenna configurations. Various channel configurations were considered including channel correlation, a measured channel model, and errors in the channel estimate. It can be seen from the results that single carrier scheme with sufficiently higher number of antennas at the base station side provides good bit error rate (BER) performance.