Channel Prediction For IMT-Advanced TDD Mode

IMT-Advanced is the Fourth Generation Mobile Communication technology standards family issued by the International Telecommunication Union (ITU). Within IMT-Advanced, Time Division Duplex (TDD) mode has become increasingly important since it is the extension of the existing TD-SCDMA (Time Division Synchronous Code-Division Multiple Access) and TD-LTE (TD-SCDMA Long Term Evolution) of China. In TDD system, uplink and downlink channels share the same spectrum, and are separated each other with time intervals. One of the advantages of TDD, relative to FDD, is the channel reciprocity. Channel reciprocity is constrained by the system coherence time, which only holds when the uplink and downlink time-slots are within the coherence time. In the practical communication environment, to take full use of TDD channel reciprocity, RF transceiver calibration technique is adopted to overcome the asymmetry between the transmitter and the receiver chains. In this report/thesis, we argue that the asymmetry of RF circuit can be overcome by system calibration. The time duration when a calibrated RF transceiver circuit lost its symmetry is much larger than the channel coherence time. Therefore, we can assume TDD channel reciprocity for channel prediction within channel coherence time given the RF circuit has been properly calibrated. In this work, we propose two channel prediction methods based on Linear Prediction and Radical Basis Function (RBF) Neural Networks for the LTE frame structure2based on TDD channel reciprocity. We analyze two channel prediction methods theoretically and evaluate the performance of single frame and Multi-frame channel prediction under different UE's speed. The simulation is fulfilled under Rayleigh channel and the existing LTE Frame Structure2where the center carrier frequency is2.6GHz.This is because the Ministry of Industry has approved the frequency band of2.6GHz to TDD mode in2010. The exact working frequency band of IMT system is from2570to2620MHz including the, guard interval.