A low complexity channel estimation scheme for Massive MIMO systems

摘要

It is well-known that Massive MIMO systems (Multiple-input multiple-output) have high potential for future wireless broadband systems. Massive MIMO (m-MIMO) relies on spatial multiplexing, and for that reason the base station needs a precise channel knowledge at uplink and downlink. Pilots can be used for channel state information (CSI) estimation, but common estimation processes imply a matrix inversion which can be a heavy computational process for m-MIMO system where the number of antennas used in the communication is very high. To alleviate computational requirements, reduce latency and to improve battery life capacity of mobile devices matrix inversion operations should be avoided. Having in mind these constrains, a new channel estimation method based on Zadoff-Chu (ZC) sequences is presented here, that achieves similar or better performance than least squares (LS) or minimum mean-Square Error (MMSE) channel estimators. It is also presented a set of performance results that sustain our assumption.