Channel estimate with PDP assumption and interference RS knowledge in LTE system
In this article, we discuss the LMMSE(linear minimum mean square error) channel estimate methods on OFDM(Orthogonal Frequency Division Multiplexing) in LTE system. To reduce the complexity of LMMSE, a constant assumption PDP(power delay profile) is used with little performance backoff. The influence of different PDP assumption and channel condition is simulated that the proposed algorithm is robust. Then we come to SRS(sounding reference signal) which different users send different sequence in the same time-frequency resources in LTE system. Simulation results show that if user number is not more than 4, the MSE performance nearly equals to single user, that is LMMSE channel estimate can cancel orthogonal RS sequence interference implicitly. DMRS(demodulation RS) estimate in CoMP scenario has also been discussed whose performance can be increased substantially with the knowledge of interference RS sequence.