Joint Time-Frequency Channel Estimation Method for OFDM Systems Based on Compressive Sensing

Time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) outperforms the classical cyclic prefix OFDM (CP-OFDM) in higher spectral efficiency and faster synchronization. However, it has the difficulty to support high-order modulations like 256QAM and suffers from performance loss especially under severely fading channels. To solve this problem, a channel estimation method for OFDM system is proposed under the framework of compressive sensing (CS) in this paper. Firstly, by exploiting the signal structure, the auxiliary channel information is obtained. Secondly, we propose the auxiliary information based compressive sampling matching pursuit (A-CoSaMP) algorithm to utilize a very few frequency-domain pilots embedded in the OFDM block for the exact channel impulse response estimation. Simulation results demonstrate that the CS-based OFDM outperforms the conventional dual pseudo noise padded OFDM and CS-based TDS-OFDM schemes in both static and mobile environments.