Title :
Joint Detection of Integral Carrier Frequency Offset and Preamble Index in OFDMA WiMAX Downlink Synchronization
Author :
Hung, Kun-Chien ; Lin, David W.
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu
Abstract :
Initial downlink synchronization in orthogonal frequency-division multiple access (OFDMA)-based WiMAX transmission involves carrier frequency synchronization, timing synchronization, and preamble index identification. Due to the structure of the preamble signal, it is reasonable to take a two-stage approach in which one first estimates and compensates the timing offset and the so-called fractional carrier frequency offset (CFO) and then deals with the integral CFO and the preamble index. This paper considers joint detection of integral CFO and preamble index, under the assumption that timing and fractional CFO have been acquired to reasonable accuracy. Based on an optimization formulation, we derive a number of detection methods of different complexity and suboptimality. The methods exploit the quasi-orthogonality among the OFDMA WiMAX preamble sequences as well as the organization of the nonzero subcarriers in the preambles. Simulation results are presented to illustrate the performance of the methods.
Keywords :
WiMax; frequency division multiple access; optimisation; signal detection; synchronisation; OFDMA WiMAX downlink synchronization; WiMAX transmission; carrier frequency synchronization; detection methods; integral carrier frequency offset; joint detection; nonzero subcarriers; optimization formulation; orthogonal frequency-division multiple access; preamble index identification; preamble sequences; timing synchronization; Communications Society; Downlink; Fading; Frequency estimation; Frequency synchronization; Interference; Oscillators; Sampling methods; Timing; WiMAX;
Conference_Titel :
Wireless Communications and Networking Conference, 2007.WCNC 2007. IEEE
Conference_Location :
Kowloon
Print_ISBN :
1-4244-0658-7
Electronic_ISBN :
1525-3511
DOI :
10.1109/WCNC.2007.367