Encoding and Decoding for Multicell Massive MIMO Systems

For a multicell, massive multiple-input multiple-output (MIMO) system with pilot reuse, pilot contamination largely degrades the performance of the system. One prominent effect caused by the pilot contamination is the existence of the error floor, that is, the error probability of the system cannot go to zero, even when the signal-to-noise ratio (SNR) of the system goes to infinity. This paper proposes new encoding and decoding schemes to reduce the error floor. In fact, based on the detailed analysis on the massive MIMO system, the design criterion of the encoding is proposed, and several concrete code design examples are given. Moreover, two decoding methods based on the oblique projection are presented, which have lower decoding complexity than the ML decoding while having good error performance. Simulation results show that our schemes have better performance than the system with the minimum mean square error (MMSE) decoder.