Open AccessBeam Coherence Time Analysis for Mobile Wideband mmWave Point-to-Point MIMO Channels
Author(s) -
Yasaman Khorsandmanesh,
Emil Bjornson,
Joakim Jalden,
Bengt Lindoff
Publication year - 2024
Publication title -
ieee wireless communications letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.23
H-Index - 72
eISSN - 2162-2345
pISSN - 2162-2337
DOI - 10.1109/lwc.2024.3381434
Subject(s) - communication, networking and broadcast technologies , computing and processing , signal processing and analysis
Multi-Gbps data rates are achievable in millimeter-wave (mmWave) bands, but a prominent issue is the tiny wavelength that results in rapid fading variations and significant pilot signaling for channel estimation. In this letter, we recognize that the angles of scattering clusters seen from the UE vary slowly compared to the small-scale fading. We characterize the beam coherence time, which quantifies how frequently the UE must update its downlink receive combining matrix. The exact beam coherence time is derived in the single-cluster case, and an achievable lower bound is proposed for the multi-cluster case. These values are determined so that at least half of the received signal gain is maintained in between the combining updates. We demonstrate how the beam coherence time can be hundreds of times larger than the channel coherence time of the small-scale fading.