Research On PN-Based Channel Estimation Method In OFDM System

Orthogonal Frequency Division Multiplexing technique (OFDM) has been widely used in modern wireless communication area due to the high spectrum efficiency, simplicity to implementation, etc. In OFDM system, channel state information is the major factor to restore the transmitted signals. In this paper, the channel estimation technique based on PN sequence is present. The characteristic of traditional algorithm is researched. PN-based turbo correlation detection in time domain was improved in some aspect, depart the channel state information into blocks according to fixed OFDM length. For each block, zeros are added and FFT operation is performed. Instead of using Lagrange interpolation method in frequency domain, cubic spline interpolation method in time-frequency 2D surface is employed and estimation precision is better than block-polite and typical algorithm. Moreover, combining the merits of LMS algorithm, PN-based LMS algorithm is proposed. Estimation precision is improved.