On joint fine time adjustment and channel estimation for OFDM systems

Abstract

This paper addresses training-sequence-based joint fine time adjustment and channel estimation for orthogonal frequency-division multiplexing systems. The proposed approach first derives an optimized threshold that adapts to the channel statistic and the signal-to-noise ratio. Then a practical suboptimal threshold is presented to avoid the estimation of the channel statistic. The suboptimal threshold requires no pre-simulations and performs as well as the optimal one. For performance analysis, the probability of perfect fine time adjustment given a particular threshold is also derived. The theoretical results agree well with the simulation results in both Rayleigh and Ricean channels.

Symbol Timing Sequence Structure for OFDM-CDMA Communication System under Low SNR

“…The corresponding performance analysis based on time-domain m-sequence preamble was provided in [8] and the closed form expression of the frame start probability of correct detection was given. As another kind of sequences with perfect periodic correlation property, constant amplitude zero auto-correlation (CAZAC) sequences were also considered to complete fine symbol synchronization [9][10][11][12]. Similar to m-sequences, CAZAC sequences can also generate a sharp correlation peak and obtain accurate timing synchronization.…”