Subspace-based blind channel estimation in CP systems by repeated use of remodulated received blocks

Blind channel estimation has been studied in various types of communication systems since it has a better bandwidth efficiency than training-based counterpart. In communication systems employed with cyclic prefixes (CP), subspace-based (SS) methods are among the most popular categories of blind channel estimation schemes. Existing SS methods, however, either require a large amount of received data or possess a high computational complexity. In this paper, a new algorithm for blind channel estimation in CP systems that require few received blocks with a reasonable complexity is proposed. The idea is based on combing advantages from two previously reported SS methods, namely, remodulation and repeated use of each received block. The combination of the two separate ideas turns out to be superior to each of them alone in many aspects. Simulation results not only confirms the capability of the proposed method to work properly with very few received blocks, but also show that it outperforms all previously reported methods. An extension of the proposed algorithm to MIMO case is promising.