Role of Channel Estimation in Physical Layer Protocol Design of OFDM Wireless Systems and Relay-Type Cooperative Communication
The authors consider the role of physical-layer signal processing functions in the design of physical-layer protocols for OFDM point-to-point and relay-type cooperative wireless communication systems. In particular, they examine the role of the channel estimation function to some depth. To effect a pointed discussion, they employ the IEEE 802.16e/WiMAX OFDMA specifications as an example to illustrate the key concepts. The discussion elucidates the implication of the pilot sub-carriers arrangement on the channel estimator design as well as the channel estimator's complexity.