Downlink Pilot Reduction for Massive MIMO Systems via Compressed Sensing

作者：Choi Jun Won^*; Shim Byonghyo; Chang Seok Ho

来源：IEEE Communications Letters, 2015, 19(11): 1889-1892.

DOI：10.1109/LCOMM.2015.2474398

• Channel estimation
• compressed sensing
• downlink pilot allocation
• massive multiple-input multiple-output (MIMO)
• orthogonal frequency division multiplexing (OFDM)

This letter addresses a problem of downlink pilot allocation for massive multiple-input multiple-output (MIMO) systems. When a massive MIMO is employed in frequency division duplex (FDD) systems, significant amount of radio resources are dedicated to the transmission of downlink pilots. Such huge pilot overhead leads to a substantial loss in the maximum data throughput, which motivates us to reduce the number of pilots. In this letter, we propose a pilot reduction strategy based on compressed sensing techniques for orthogonal frequency division multiplexing systems. The pilots are randomly located in a low density manner over the time and frequency domain. To estimate the channels with such low density pilots, we propose a novel sparse channel estimation technique that exploits the common support of the consecutive channel impulse responses over the certain time duration. The evaluation shows that for a massive MIMO with 128 antennas, the proposed scheme achieves significant reduction of pilot overhead, while maintaining good channel estimation performance.

• 出版日期2015-11