Channel Estimation for Spatial Modulation Schemes in Spatially Correlated Time Varying Channels

• In this paper, we propose a channel estimation scheme for spatial modulation (SM) systems. In general, SM systems require each transmit antenna to separately send pilot symbols for channel estimation. This is a lengthy process, which may incur significant channel estimation errors in a time varying channel. Thus, we propose correlation-based channel estimation (CBCE) scheme, which exploits the correlation between transmit antennas to estimate channels of inactive antennas using the pilot-based estimate of the active antenna. The change in the active channel from the last pilot-based estimate is calculated, and a time-proportionate amount of that change is scaled according to the channel correlation coefficients to estimate the channel state of the inactive channels. With pilot slots designed to spread out in a data frame, the estimation process for every channel is carried out $N_t$ times in a data frame with $N_t$ denoting the number of transmit antennas. We observe that in a high signal-to-noise ratio (SNR) regime, our proposed scheme provides about 2 dB and 5 dB gains compared to conventional channel estimation (CCE) method for moderately correlated and highly correlated antennas, respectively. Through Monte Carlo simulations with different correlation $\rho$ and user speeds, we validate our analysis and show that the proposed scheme outperforms CCE when $\rho \geq 0.3$, while it provides comparable performance for small $\rho$. © 1967-2012 IEEE.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Kommunikationssystem (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Communication Systems (hsv//eng)

Nyckelord

channel estimation

MIMO

spatial correlation

Spatial modulation (SM)

time-varying channels

Modulation

Monte Carlo methods

Slot antennas

Time varying networks

Channel correlation

Channel estimation errors

Estimation process

High signalto-noise ratios (SNR)

Highly-correlated

Spatial modulations

Time varying channel

Transmit antenna

Signal to noise ratio

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)