Low-Complexity Channel Estimation for 3GPP LTE Terminals

Abstract:
The 3GPP Long Term Evolution (LTE) system provides higher data rates than ever previously achieved in mobile communications. To achieve high data rates, especially under critical fading channels, accurate channel estimation is necessary. This usually leads to high complexity of the receiver. Therefore, it is critical to reduce the computational complexity of the channel estimation algorithm for a practical implementation, while at the same time maintaining the high performance. In this paper, problems on reducing computational complexity of the MMSE-based channel estimation algorithm for 3GPP LTE terminals are systematically investigated, and a practical highperformance and low-complexity algorithm is then proposed. The performance and computational complexity of the proposed algorithm are evaluated and compared with commonly used channel estimation algorithms under realistic environments. For the 5 MHz 2x2 LTE system and for the same throughput, the performance loss of the proposed algorithm compared with the full-size MMSE algorithm is within 1 dB channel SNR, whereas its computational complexity is reduced by about four orders. As a result, it can be cost-effectively implemented.