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In this contribution a novel Frequency Coded (FC) chipless RFID system is introduced to significantly enhance the tag detection. The proposed system exploits the properties of Pseudo Noise (PN) random sequence, as a transmitted signal, to accurately estimate the Channel Impulse Response (CIR). Consequently, the undesired environmental clutter is filtered by a Selective-RAKE receiver. Hence, the tag...
We propose a differential space-time coded (STC) radio-frequency-identification (RFID) system where the tag has two antennas and the reader has a single or multiple antennas. In this system, the M-ary phase-shift keying constellation is used, and encoding at the tag and decoding at the reader are simple. Simulation results show that the proposed STC RFID system can achieve a performance improvement...
Up to now, a closed-form expression of the ergodic capacity for amplify-and-forward opportunistic relaying in the presence of outdated channel state information(CSI) is still not available in the literature. That is mainly due to the mathematical intractability in the conventional performance analysis through manipulations of probability density function (PDF). In this paper, therefore, we take advantage...
A new modulation scheme combing GMSK with direct-sequence spread spectrum (DSSS) and differential modulation is proposed in this paper, which is named DS-DGMSK. The demodulation can achieve BER performance comparable to DBPSK while the bandwidth efficiency and power efficiency are higher thanks to GMSK. By combining with spread spectrum and differential demodulation, the scheme is robust at low SINR...
We consider an angular distribution for modeling the local scattering in the vicinity of the receiver or the transmitter. The Gaussian spatial distribution is extended to capture the correlation between the x-coordinate and the y-coordinate, which gives rise to a generalization to the uncorrelated Gaussian spatial distribution. The probability density function of the correlated Gaussian spatial distribution...
Spatial frequency approximation (SFA) of spatial fading correlation (SFC) is addressed for the case that the exact infinite summation of Bessel functions is inconvenient or infeasible. The angular spread is derived for semicircular scattering, especially characterized by uniform, Gaussian, Laplacian, and von Mises distributions. The semicircular scattering on the range (-1over2π, 1over2π] happens,...
In this paper, bit error rate (BER) analysis is presented for ultra-wideband (UWB) multiple-input multiple-output (MIMO) cooperative relay systems, where partial channel state information (CSI) is only available at the receiver side. In the analysis, decouple-and-forward (DCF) and decode-and-forward (DF) relaying schemes are considered. For these schemes, the relay regions, in which cooperative relaying...
We consider the transmission rate over the multiantenna ultrawideband channel taking into account antenna element time delays. Some algebraic inequalities are explored to formulate the upper bounds on channel capacity. For an uncorrelated fading, the upper bounds can be derived in closed forms. Numerical examples illustrate that in IEEE 802.15.4a channel model, i) the channel capacity tends to be...
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