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Channel estimation error problem is among the main causes of performance degradation in wireless networks. In this paper, we investigate the impact of channel estimation error on cooperative communications. We analyze the symbol error rate (SER) performance of decode-and-forward (DF) cooperative communications with channel estimation error over nakagami-m(More)
In this paper, the design problem and the robustness of space-frequency trellis codes for MIMO-OFDM systems are studied. We find that the channel constructed by the consecutive subcarriers of an OFDM block is a correlated fading channel with regular correlation function of the number and time delay of the multipaths. We decompose the correlated fading(More)
The recursive least squares (RLS) algorithm and the superimposed training sequences are applied to the orthogonal frequency division multiplexing (OFDM) systems to estimate channel state information (CSI). In order to reduce the interference caused by the unknown information data that is added with the superimposed training sequences, we present the(More)
Recently, the antenna selection (AS) scheme is a hot topic in the region of multiple-input multiple-output (MIMO) systems, due to lower complexity. In the previous research, it is assumed that the channel state information (CSI) is available at the receiver, which, however, is impractical in the wireless transmission environment. During the process of the(More)
In this paper, we propose a new dual-band filtering method for performance enhancement of the chirp spread spectrum (CSS) system in the IEEE 802.15.4a standard. The CSS signals are composed of low- and high-band signals which are alternatively transmitted in time. If we use only one conventional channel filter, the signal-to-noise ratio (SNR) performance in(More)
The minimum mean-square error (MMSE) channel estimation has well performance but higher complexity than least-square (LS) channel estimation, specially it requires the channel statistical properties including the channel autocorrelation matrix and the noise variance. However, it is difficult to obtain the channel statistical properties in practice. In this(More)
In this paper, we propose a simple joint transmit and receive antenna selection algorithm based on maximizing the instantaneous signal to noise ratio (SNR) over uncorrelated Rayleigh fading channels in multi-input multi-output (MIMO) systems. For a special case that two transmit antennas and one receive antenna are selected, while Alamouti scheme is(More)
Linear least squares (LLS) estimation is a low complexity but sub-optimum method for estimating the location of a mobile terminal (MT) from some measured distances. It requires selecting one of the known fixed terminals (FTs) as a reference FT for obtaining a linear set of expressions. In this paper, a new method for selecting the reference FT is proposed,(More)