Successive Cancellation Integer Forcing via Practical Binary Codes

A new multiple-input multiple-output (MIMO) receiver scheme for practical binary codes is proposed that provides consistent gains over conventional linear receivers. We first develop a practical successive integer forcing (IF) scheme based on practical binary codes rather than lattice codes. We then present the successive cancellation integer forcing (SC-IF) scheme, which combines and enhances successive IF and minimum mean squared error successive interference cancellation (MMSE-SIC). In this scheme, the receiver first decides whether individual decoding or IF sum decoding is appropriate for each data stream, and then conducts successive IF sum decoding only for selected streams while decoding the remaining streams using MMSE-SIC. The proposed SC-IF methodology mitigates the performance loss caused by mismatched IF filtering in fading channels, while attenuating the noise amplification caused by MMSE filtering. Extensive link-level simulations demonstrate that the proposed successive IF significantly improves the basic IF, and the SC-IF improves both the successive IF and MMSE-SIC, offering uniform improvements over conventional linear receivers for most channel correlation and variation parameters and modulation orders at comparable computational costs. These results illustrate the viability of SC-IF as a fundamental building block for high-performance MIMO receivers in 5G-Advanced and/or subsequent-generation communication systems.

I. Introduction

In recent years, the volume of mobile data traffic has increased dramatically. In particular, global mobile data traffic has reached 51 Exabytes (EB) per month by the end of 2020, and is projected to increase by a factor of 4.5 to 226 EB per month by 2026 [1]. The fourth-generation cellular system cannot fully support emerging new services that are driving this trend, such as 4K streaming and virtual/augmented reality from interactive live concerts and sporting events for immersive experiences on mobile devices. To fulfill such enhanced mobile broadband (eMBB) usage scenarios, the fifth generation (5G) system would be required to produce three times more spectral efficiency than its predecessor [2]. This is anticipated to be done by a more efficient utilization of wireless spectrum. As a result, it is imperative to build a low-complexity multiple-input multiple-output (MIMO) receiver capable of delivering high performance while scaling with many antennas and large constellations.