Low‐complexity receivers for massive MIMO‐GFDM communications

Abstract

AbstractThe orthogonal frequency division multiplexing (OFDM)‐based modulation scheme is widely utilized in asymmetric digital subscriber lines (ADSL), wireless local area networks (WLAN), and the fourth generation (4G) of mobile communication systems due to its ability to cope with severe channel conditions without complex equalization processes. However, the drawbacks of OFDM such as: requirement of a high peak to average power ratio (PAPR) radio frequency (RF) power amplifier, sensitive to carrier frequency offset, high out‐of‐band (OOB) emissions cause the OFDM is not applicable for the fifth generation (5G) mobile communication application scenarios such as machine‐type communications (MTC), Internet of things (IoT), and cognitive radio (CR). Generalized Frequency Division Multiplexing (GFDM) modulation scheme has regarded as one of the promising candidates for 5G waveforms due to its properties, such as low latency, low OOB emission, robust against carrier frequency offset (CFO), and time offset (TO). The GFDM is also combined with massive multiple‐input multiple‐output (MIMO) technology that equipping each base station (BS) with an array of many active antennas, which are used to spatially multiplex many user equipment (UE) to improve spectrum efficiency (SE). However, as the modulation order and the number of antennas increases, the complexity of the maximum likelihood (ML) detector and the minimum‐mean‐square‐error (MMSE) detector causes an impediment for real‐world applications. This paper proposes a low‐complexity detector configuration which utilizes quadratic programming principle. The simulations show that the computation complexity of the proposed detector is lower than the ML detector and the bit‐error‐rate performance of the proposed detector is better than that of the MMSE detector.