Bandwidth efficient power‐aided semi‐blind channel estimation for multiple‐antenna systems

Abstract

This study presents a semi-blind channel estimation scheme for multiple-antenna systems. With the aid of channel covariance and received signal power, the proposed scheme derives channel estimates using pilot symbols transmitted by only one of its antennas. Other transmit antennas in the scheme do not need to transmit any pilot symbols. As such, the proposed scheme has higher bandwidth efficiency compared with conventional pilot symbol-based multiple-antenna channel estimation schemes, where every antenna is required to transmit pilot symbols. It is shown that the proposed scheme is able to deliver performance on par with the conventional minimum mean-square error and least-square error multiple-channel estimation schemes. The strength of the proposed scheme lies in its ability to exploit received signal power for channel estimation.

Orthogonal space-time block codes for large MIMO systems

“…The advantages of utilising multiple antennas, such as transmit and receive spatial diversity, have been known and exploited for some time [1][2][3]. Recent implementation of MIMO includes its utilisation in mobile wireless systems such as Long Term Evolution-Advanced (LTE-A) and Worldwide Interoperability for Microwave Access (WiMAX), as well as its incorporation in the wireless local area networks IEEE 802.11n standard [4][5].…”

Novel polar-coded space-time transmit diversity scheme over Rician fading MIMO channels

“…The gain coefficient of the equivalent channel is expressed as h = |h 11 | 2 + |h 21 | 2 + |h 31 | 2 + |h 41 | 2 + |h 12 | 2 + |h 22 | 2 + | h 32 | 2 + |h 42 | 2 . We can substitute n = 8 to function (9). Now, the PDF of the initial LLR can be expressed as…”

“…Each output y i can still be regarded as a Gaussian random variable with mean h and variance hσ 2 n . Substitute n = 4 to function (9) to get the distribution of h. The PDF of the initial LLR is as follows…”

“…Diversity is an efficient technique to combat multipath fading in MIMO channels. The effect of transmit and receive diversity can be enhanced as the number of antennas increases [8,9]. Space-time transmit diversity (STTD) can achieve a full diversity gain with a simple structure, which can be regarded as a process of coding.…”