An Efficient Joint Algorithm of Synchronization, Channel Estimation and the Low Peak-to-Average Power Ratio for OFDM System

Orthogonal frequency division multiplexing (OFDM) is a multi-carrier transmission technique, which divides the available spectrum into many subcarriers, each one being modulated by a low data rate stream[1]. Compare with the traditional ways, the OFDM system has the features of resisting frequency selective fading and high frequency-band utility ratio and so on. OFDM has been successfully applied to a wide variety of digital communication applications over the past several years. OFDM system is sensitive to carrier frequency offset (CFO) and it requires a high degree of synchronization precision. Many techniques have been presented for synchronization in OFDM receivers [2]-[4]. Some of them are based on pilot, and others on the cyclic prefix(CP) of the OFDM symbols. Channel estimation is the key part in OFDM receivers. A method to estimate channel presented in [5] is data-aided. In reference [6], the channel estimation algorithm is based on pilot. OFDM system exploits the orthogonal subcarriers to transmit the data parallelly. It may give Abstract:Based on the key technology of high data rate wireless communication systems—Orthogonal Frequency Division Multiplexing(OFDM), an efficient joint algorithm is proposed. This method can realize synchronization, channel estimation and the low peak-to-average power ratio of OFDM system. To do this, the OFDM system exploits a training sequence to achieve synchronization and channel estimation, and to lower the peak-to-average power ratio with the coefficients of partial transfer sequece (PTS) algorithm. Results of simulations indicate that the OFDM system with the joint algorithm can simultaneously realize synchronization, channel estimation and the low peak-to-average power ratio and be implemented with reduced complexity and improved validity by using one training sequence.