Parallel Semi-blind Joint Timing-Offset and Channel Estimation for AF-TWRNs

AbstractTime Domain Synchronous Orthogonal Frequency Division Multiple Access (TDS-OFDMA) is used in mobile broadband wireless access scheme in uplink transmission. This leads to multiple user interference due to timing offset and frequency offset. In this paper, the effect of timing offset and channel estimation in mobile broadband system is analysed. Time-space two dimensional structure is used in TDS-OFDMA and perfect sequence is used for guard interval to achieve perfect timing synchronization and channel estimation for each user. Simulations are performed for timing synchronization and channel estimation using perfect sequence under Urban channel, Indoor Office B channel and HIPER LAN-A channel. Simulation results show that the timing synchronization is achieved and channel estimation performance using perfect sequence is better than CAZAC and PN Sequences.

Download Full-text

Channel estimation with timing offset based on PSD & LS estimation for wireless OFDM systems

2007 International Symposium on Intelligent Signal Processing and Communication Systems ◽

10.1109/ispacs.2007.4445870 ◽

2007 ◽

Author(s):

Shengping Qin ◽

Peide Liu ◽

Xin Zhang ◽

Laibo Zheng ◽

Deqiang Wang

Keyword(s):

Channel Estimation ◽

Ofdm Systems ◽

Timing Offset

Download Full-text

Timing Offset Correction and Channel Tap Estimation of OFDM Systems Over Frequency Selective Fading Channels

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a1157.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1328-1333

Keyword(s):

Channel Estimation ◽

Fading Channels ◽

Estimation Error ◽

Cyclic Prefix ◽

Timing Synchronization ◽

Ofdm Systems ◽

Timing Offset ◽

Offset Correction ◽

Optimum Channel

In OFDM systems we need to perfectly time synchronize the receiver to the transmitter to maximize its BER performance. In the absence of timing synchronization the channel estimation can never be optimum. Both timing synchronization and optimum channel estimation are the essential requirements to maximize the performance. We present an algorithm that uses the cyclic prefix to determine the timing offset of the system. The same algorithm can be used to determine the number of channel taps and their variances also. Determination of number of channel taps helps us in minimizing the length of the cyclic prefix to be added and also in the channel estimation, to minimize the variance of the estimation error. The knowledge of the variances of the channel taps helps us in further reducing the estimation error. We present in this paper the timing offset corrected MMSE channel estimation and show by simulations the effectiveness of the method presented.

Download Full-text