A Multi-Antenna Pilot Predistortion Scheme and Channel Estimation Algorithm for LTE-Based Terrestrial Broadcast System

Multi-Antenna technology is a physical layer technique widely used in mobile communication and terrestrial broadcast systems. For fully utilizing the antenna diversity, conventional Multi-Antenna pilots usually meet the characteristic of orthogonality in terms of the pilot arrangement to avoid inter-pilot interference between different transmitting antennas. However, the scheme with orthogonality leads to the doubling of the pilot overhead, which seriously reduces the transmission efficiency. The latest LTE-based terrestrial broadcast system, Further evolved Multimedia Broadcast Multicast Service (FeMBMS), is probably to adopt the Multi-Antenna technique in the future, but no corresponding pilot scheme has been provided. This paper proposes a novel pilot pre-distortion scheme and Channel Estimation (CHE) algorithm for FeMBMS. The pre-distortion scheme does not require the pilot on different antennas to meet the restriction of orthogonality, so to address the problem of pilot overhead doubling. Meanwhile, it deals with the issue of inter-pilot interference by converting the interference into the white noise spreading over the whole OFDM symbol. Furthermore, the proposed CHE algorithm effectively eliminates the whitened interference by utilizing the processing of DFT-based windowing and Iterative Interference Cancellation (IIC). Simulation shows that the pre-distortion scheme and CHE algorithm could provide a CHE performance with accuracy same or close to that of the orthogonality scheme while significantly improving the transmission efficiency.