Low power consumption detectors for mmWave massive MU-MIMO-GFDM systems

Abstract

ABSTRACT The International Mobile Telecommunications-2020 (IMT-2020) specifies the data rates for enhanced mobile broadband (eMBB) is approximately 10 Gb/s. Millimetre-wave (mmWave) has a vast spectrum and can be used with only slight authorisation, making it an ideal solution for eMBB. This paper proposes optimal detectors with low cost, low power consumption, and low complexity for mmWave massive multi-user multiple-input multiple-output (MU-MIMO) communication. The mmWave broadband communication faces many challenges in system implementation. One of the challenges of mmWave broadband systems is using the analog-to-digital converter (ADC) in the receiver. The ADC power consumption will significantly increase with the frequency bandwidth. The ADC power consumption will also considerably increase with the bit number used in the conversion simultaneously. The mmWave broadband communication also challenges the cost of transmitters, especially wideband linear amplifiers are costly. Hence, it is necessary to transmit a signal with a low peak-to-average power ratio (PAPR) to relax the linearity of the power amplifier. The radio-frequency (RF) port connects to two high-precision ADCs in conventional MIMO systems. Scaling such architectures to massive multiple-input multiple-output (MIMO) with hundreds or thousands of active antenna elements would lead to excessive-high power consumption and hardware costs. Hence, this paper proposes optimal detections for massive multi-user (MU) MIMO-GFDM communications with coarse quantisation. It achieves substantial cost and power savings and provides a high system capacity. The optimal detections for coarse quantisation in large-scale MU-MIMO-GFDM systems have minimal capability loss compared with the ideal case. There is no additional base-band processing complexity. The simulation results show that the SNR gap between the second mismatched quantiser and the precise quantiser is small. When the ratio of receiving and transmitting antennas is the same, the larger the number of antennas, the smaller the SNR difference between the second mismatch quantiser and the precise quantiser.