Memory and computation reduction for least-square channel estimation of mobile OFDM systems

Mobile OFDM refers to OFDM systems with fast moving transceivers, contrastive to traditional OFDM systems whose transceivers are stationary or have a low velocity. In this paper, we use Basis Expansion Models (BEM) to model the time-variation of channels, based on which two least-squares (LS) channel estimators are presented. The first channel estimator allows for a general BEM assumption, and thus is called as the general implementation, whereas the second one is particularly tailored for a specific Critically-sampled Complex Exponential (CCE) BEM assumption, leading to a simplified architecture. The experimental results show that the simplified estimator is an appealing alternative, which achieves roughly a reduction of 59% for the ASIC core area, 89% for the ROM size and 53% of the processing latency at the cost of a slight estimation accuracy penalty compared to the general implementation method.