Complexity-Reduced Channel Estimation in Spatially Correlated MIMO-OFDM Systems

Abstract

SUMMARYThe performance of a MIMO-OFDM system significantly depends upon the accuracy of the channel impulse response (CIR) estimates. In the presence of correlation between the CIRs of the transmit or receive antennas, it is desirable to exploit this correlation to improve the performance of CIR estimation. In this letter, we propose a low-complexity channel estimation filter composed of four concatenated one-dimensional Wiener filters which are optimized to the channel characteristics in the time and frequency domains, and the transmit and receiver antenna front ends, respectively. Finally, the performance of the proposed scheme is verified.

3D Pilot Aided Channel Estimation

“…The received signal (1) applies to a mobile receiver equiped with a single receive antenna; the extension to multiple receive antennas is treated in [11][12][13]. In case of MIMO-OFDM with uncorrelated receive antennas, where channel estimation for each receive antenna is carried out independently, (1) directly applies.…”

“…In case of MIMO-OFDM with uncorrelated receive antennas, where channel estimation for each receive antenna is carried out independently, (1) directly applies. When receive antennas are correlated, the accuracy of the channel estimates may be improved by spatial smoothing of the received pilots over the receive antennas [11][12][13].…”

“…Spatial correlation between antennas is exploited in [10,11] to improve the channel estimation accuracy. An alternative approach is pursued in this paper: spatial correlation is exploited to reduce the Three dimensional (3D) pilot grid applicable to MIMO-OFDM systems where transmit antennas are spatially correlated.…”

Bandwidth efficient 3D pilot design for MIMO-OFDM

“…Due to its favorable trade-off between achieved channel estimation accuracy and required pilot overhead, 2D-PACE has been selected for a wide range of wireless communication standards, such as terrestrial digital video broadcasting (DVB-T) [6], and for B3G mobile communication systems [7]. Considering MIMO-OFDM, the principle of channel estimation by interpolation can be extended to the spatial domain, in case transmit antenna elements are spatially correlated, giving rise to three dimensional (3D) PACE [8][9][10].…”

“…The received signal (1) applies to a mobile receiver equipped with a single receive antenna; the extension to multiple receive antennas is treated in [9,13,14]. In case of MIMO-OFDM with uncorrelated receive antennas, where channel estimation for each receive antenna is carried out independently, (1) directly applies.…”