Gridless Channel Estimation for MmWave Systems with Non-Ideal Pulse Shaping Filters

In this paper, we consider channel estimation for wideband millimeter-wave (mmWave) systems with non-ideal pulse shaping filters. The use of non-ideal pulse shaping filters complicates the channel estimation problem. In the literature, such a problem has been addressed using oversampling or on-grid methods. We show that gridless estimation can be achieved for a orthogonal frequency-division multiplexing (OFDM) system with non-ideal pulse shaping filters. By using an appropriately chosen subset of subcarriers of the OFDM system, the estimation of a wideband mmWave channel is converted to a harmonic retrieval problem, which can be solved efficiently using gridless algorithms. Simulations are given to show that the proposed method enjoys high estimation accuracy with low complexity.