Interference-avoidance pilot design using ZCZ sequences for multi-cell MIMO-OFDM systems

In this paper, we propose an interference-avoidance pilot design scheme using Zero-Correlation Zone (ZCZ) sequences for multi-cell MIMO-OFDM systems. In the proposed scheme, the ZCZ sequences from the same family set are designed as the time-domain (TD) pilot symbols and are Code-Division Multiplexing (CDM) for different transmit antennas in adjacent cells. Due to the perfect auto-correlation and cross-correlation properties of the ZCZ sequences within a certain correlation zone that is designed equal to or a little larger than the Cyclic Prefix (CP) length, the inter-cell interference of the pilot symbols can be effectively eliminated by utilizing a time-domain correlation-based channel estimation method. Simulation results show that the proposed scheme achieves near optimal normalized Mean Square Error (MSE) performance of channel estimation in a multi-cell environment.