Exploring Uplink Achievable Rate for HPO MIMO Through Quasi-Monte Carlo and Variance Reduction Techniques

The power consumption at the receiver side will be dramatically increased in the millimetre-wave and massive multiple-input-multiple-output (MIMO) communication systems due to the wide bandwidth and a large number of antennas adopted. A half phase-only MIMO (HPO MIMO) scheme, in which the base station (BS) acquires $\pi $ -periodic phase measurements of the complex envelop signals was proposed very recently to overcome the above problem. Due to the non-linear nature of HPO MIMO, the valuation of the achievable rate is very challenging. The purpose of the paper is to provide an efficient method for calculating the achievable rate of the HPO MIMO system. By the mutual information theory, we transform the achievable rate into a sum of two high-dimensional integrations. However, calculating those integrations suffers from the enormous computational burden when using the traditional Monte-Carlo method. In order to increase efficiency, a new method by combining quasi-Monte Carlo with a variance reduction technique is proposed. Besides, we derive the probability density function (PDF) of the HPO MIMO system and analyze the uplink achievable rate of the HPO MIMO scheme. Numerical results show that our proposed method is efficient for calculating the achievable rate of the HPO MIMO system. With the proposed method we confirm that HPO MIMO is a promising technology in future low-power communication scenarios.