MIMO channel estimation algorithm using complete complementary sequence

Abstract

Multiple-input multiple-output (MIMO) channel estimation algorithm is proposed in this paper. A pilot scheme that uses complete complementary sequence (CCS) with complete orthogonality (the sidelobes of the auto-correlation function and cross-correlation function equals zero for all time shifts) was investigated in order to eliminate the mutual interference between multiple antennas. The channel estimation performance under the normalized mean square error sense (NMSE) based on CCS is derived. Results from simulated data, the efficiency and validity of the CCS applied in MIMO channel estimation are proved. The CCS opens up a new direction for channel estimation in the future wireless communication systems. Compared with traditional pilot scheme in the frequency domain, the proposed channel estimation algorithms in the time domain need not matrix inversion which can reduce the computational complexity. In contrast to the complementary pilot mode, CCS-based channel estimation acquired much more flexible configuration in selection of transmitter antenna number. At the same time, compared with the pilot sequence based on m sequence, the channel estimation performance is improved by using the orthogonality of the CCS.