Title :
Initial synchronization assisted from inherent diversity on LTE sector search process
Author :
Jia-Chin Lin ; Yu-Ting Sun
Author_Institution :
Dept. of Electr. Eng., Princeton Univ., Princeton, NJ, USA
Abstract :
Estimations of time error and frequency offset upon initial synchronization are investigated in this paper as components of the sector search process in third-generation partnership project (3GPP) long-term evolution (LTE) communications. The proposed system considers intercell interference, inter-carrier interference and multipath fading by exploiting various diversity. A coarse timing alignment is achieved by the acquisition of a primary synchronization sequence. The coarse timing alignment extracts autocorrelation at a long lag of one half of a frame length from the decimated signal at a lower sampling rate by exploiting a differential correlator. Estimations of residual time error and fractional frequency offset are achieved by evaluating the short-lag autocorrelation at an OFDM symbol duration. The estimations utilize 70 cyclic prefixes that are pre-stored in the buffer employed in the aforementioned differential correlator. The estimations can effectively overcome the time variation of the channel that occurs as a result of a Doppler spread. Comprehensive computer simulations are conducted to verify that the proposed technique can effectively overcome inter-cell interference, time-selectivity, and multipath fading, thereby achieving low estimation errors.
Keywords :
Long Term Evolution; OFDM modulation; estimation theory; fading channels; intercarrier interference; multipath channels; search problems; 3GPP; Doppler spread; LTE communications; LTE sector search process; OFDM symbol duration; coarse timing alignment; differential correlator; fractional frequency offset; inherent diversity; initial synchronization; intercarrier interference; intercell interference; long term evolution; multipath fading; residual time error; sector search process; third generation partnership project; time error estimation; Correlation; Estimation; Fading; Interference; OFDM; Synchronization;
Conference_Titel :
Wireless Communications and Networking Conference (WCNC), 2015 IEEE
Conference_Location :
New Orleans, LA
DOI :
10.1109/WCNC.2015.7127486