Summary
International Symposium on Antennas and Propagation
2008
Session Number:2D04
Session:
Number:2D04-2
AP Line Search-based Joint Estimation of Carrier Frequency Offset and Channel Response in Uplink OFDMA
Hsien-Kwei Ho, Jean-Fu Kiang,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
Orthogonal frequency-division multiple access (OFDMA) is a promising technique for the 4th generation (4G) systems. To decrease the computing time of grid search in carrier frequency offset (CFO) estimation, several different optimization approaches have been applied, such as direct line search [5] and ad hoc [1], which are highly related to the characteristics of the target problem. In this work, one pilot preamble symbol is transmitted as a training sequence. The coarse frequency offset has been adjusted by assuming that the subscriber stations (SSs) have synchronized with the base station (BS) by down-link signals. The maximum-likelihood estimation can be conducted in the preamble transmission. To increase the efficiency of optimization, the system model is analyzed through matrix products. Alternating projection method is used as an example, where line search method is adopted to simply the frequency offset search. The system model will be derived in section 2, the alternating projection method in section 3, simulation results and conclusion in section 4.