An energy efficiency perspective on massive MIMO quantization

Abstract

Abstract-One of the basic aspects of Massive MIMO (MaMi) that is in the focus of current investigations is its potential of using low-cost and energy-efficient hardware. It is often claimed that MaMi will allow for using analog-to-digital converters (ADCs) with very low resolutions and that this will result in overall improvement of energy efficiency. In this contribution, we perform a parametric energy efficiency analysis of MaMi uplink for the entire base station receiver system with varying ADC resolutions. The analysis shows that, for a wide variety of system parameters, ADCs with intermediate bit resolutions (4 -10 bits) are optimal in energy efficiency sense, and that using very low bit resolutions results in degradation of energy efficiency.

Joint Automatic Gain Control and Receiver Design for Quantized Large-Scale Mu-Mimo Systems

“…Therefore, low-resolution ADCs are a solution to save energy in this kind of system. Furthermore, the adoption of lower bitprecision ADCs allows complexity reduction, faster signal processing, costs reduction, and also relieves the capacity bottleneck of the FH links by reducing the amount of data that have to be transported [16][17][18][19][20][21][22].…”

“…In practical systems, the ADC is usually preceded by an automatic gain control (AGC) variable gain amplifier, which aims to minimize the overload distortion [19]. The AGC adjusts conveniently the analog signal level to the dynamic range of the ADC.…”

“…The impact of low-resolution ADCs on the performance of communication systems has been widely studied in the literature [16][17][18][19][20][21]23,[25][26][27][28][29][30][31]. Nevertheless, few studies address the design of AGCs.…”

“…However, the other side of the coin of MIMO systems is that the simultaneous transmission of the multiple data streams can interfere with each other, which can make the detection and the decoding process at the receiver more complicated. Another point to be considered is when the number of antennas that are employed increases and, as the number of A/D and D/A converters is twice the number of antennas, the energy consumption of the system also grows [16][17][18][19][20][21].…”

“…Among the hardware components, the ADC has attracted growing interest. The motivation of such growing interest is that the power consumption of ADCs grows exponentially with the number of bits and linearly with sampling rate or with the system bandwidth [19,61,72]. Then, the energy consumption of the ADCs directly interferes in the energy consumption bottleneck of systems which employs a high number of antennas [16,18].…”