Doubly Selective Channel Estimation Using Superimposed Training and Exponential Bases Models

• Published in: EURASIP Journal on Advances in Signal Processing
• Main Authors: Tugnait Jitendra K, Meng Xiaohong, He Shuangchi
• Format: Article in Journal/Newspaper
• Language: English
• Published: SpringerOpen 2006
• Subjects: Telecommunication; TK5101-6720; Electronics; TK7800-8360; Simo; DML
• Online Access: https://doaj.org/article/e350f336db48438a9bfce544db9763c2

Channel estimation for single-input multiple-output (SIMO) frequency-selective time-varying channels is considered using superimposed training. The time-varying channel is assumed to be described by a complex exponential basis expansion model (CE-BEM). A periodic (nonrandom) training sequence is arithmetically added (superimposed) at a low power to the information sequence at the transmitter before modulation and transmission. A two-step approach is adopted where in the first step we estimate the channel using CE-BEM and only the first-order statistics of the data. Using the estimated channel from the first step, a Viterbi detector is used to estimate the information sequence. In the second step, a deterministic maximum-likelihood (DML) approach is used to iteratively estimate the SIMO channel and the information sequences sequentially, based on CE-BEM. Three illustrative computer simulation examples are presented including two where a frequency-selective channel is randomly generated with different Doppler spreads via Jakes' model.