Abstract
Millimeter wave (mmWave) systems rely on accurate channel state information (CSI) for the design of the precoding and combining matrices. Acquiring accurate CSI, however, is challenging due to the large number of antennas, the low signal-to-noise (SNR) ratio before beamforming, and possible interference from neighboring base stations (BSs). Prior work on channel estimation focused on the first two challenges and did not address inter- cell interference. Interference from neighboring BSs deteriorates the already low SNR and introduces errors in the channel estimate. This leads to additional interference in the system. This paper studies the effects of inter- cell interference on compressed sensing (CS) mmWave channel estimation techniques. A CS measurement matrix design is then proposed to jointly estimate the mmWave channel and null interference from neighboring BSs. Simulation results show that channel estimate errors strongly depend on the interference power and the number of interfering BSs. Moreover, in the presence of interference, the proposed techniques are shown to achieve channel estimates comparable to interference-free systems.