Title :
A new ranging method for OFDMA systems
Author :
Fu, Xiaoyu ; Li, Yinghui ; Minn, Hlaing
Author_Institution :
Dept. of Electr. Eng., Texas Univ., Richardson, TX
Abstract :
We present a new initial ranging method for OFDMA systems such as IEEE 802.16-2004. First, a new orthogonal ranging signal design is proposed by which an efficient, low-complexity multi-user ranging signal detection is developed. Based on the ranging signal detector results, power estimation for the detected ranging subscriber stations is performed. Then, by utilizing the proposed orthogonal ranging signal design together with the redundancy introduced by cyclic prefixes, a new iterative multi-user timing offset estimator is presented. Compared with the existing methods utilizing the CDMA-type ranging codes (in frequency-domain) defined in IEEE 802.16-2004, the proposed method achieves a better performance and greater robustness against multi-user interference and multi-path fading channels
Keywords :
OFDM modulation; WiMax; code division multiple access; fading channels; frequency division multiple access; multipath channels; multiuser detection; radiofrequency interference; CDMA-type ranging codes; IEEE 802.16-2004; OFDMA systems; low -complexity multiuser ranging signal detection; multipath fading channels; multiuser interference; multiuser timing offset estimator; orthogonal ranging signal design; ranging method; ranging subscribe stations; Detectors; Downlink; Fading; Frequency synchronization; Interference; OFDM; Robustness; Signal design; Signal detection; Timing;
Journal_Title :
Wireless Communications, IEEE Transactions on
DOI :
10.1109/LCOMM.2007.05323
