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In this paper, we study the multiplexing throughputs of open- and closed-loop multiple-input multiple-output (MIMO) systems with fixed modulation and coding (i.e., fixed maximum data rate). For the open-loop case, we assume the simplest linear decoder, i.e., zero forcing (ZF). For the closed-loop case, we assume singular value decomposition (SVD). Using the threshold receiver model (accounting for...
In this paper, we derive Capacity per unit bandwidth (Spectrum Efficiency) of Correlated Rayleigh Fading Channels under Selection Combining Diversity at Low average SNRs. This paper provides closed-form expressions for Spectrum efficiency among M diversity branches under different adaptation policies, like (i) Optimal Power and Rate Adaptation (OPRA) policy, (ii) Optimal Rate Adaptation (ORA) policy...
This paper considers the transmission of confidential data over a quasi-static fading wiretap channel where the main and eavesdropper channels are correlated. Assuming that before transmission the transmitter knows the channel state information (CSI) of the main channel, we derive the secrecy outage probability in a closed-form expression based on a new secrecy outage probability formula, which gives...
One of the effects of scintillation caused by atmospheric turbulence is the dependence of spatial correlation on the strength of turbulence itself. This has the effect that the apertures of a multielement array while fully uncorrelated in the case of deep fading become correlated as scintillation becomes milder. In such cases the diversity effect of the MIMO array may disappear. This phenomenon is...
In this paper we propose a frequency domain equalization scheme for the cyclic prefix assisted (CPA) cyclic code shift keying (CCSK) system. In particular, the proposed scheme performs both correlation and decision in the frequency domain, which helps to reduce the computational complexity. Simulation results show that the proposed system achieves the best bit error rate (BER) performance with the...
In this paper, we have studied some important statistical properties of error sequences of M-ary orthogonal frequency-shift keying (FSK) modulation schemes over Nakagami-m fading channels. We have derived the joint probability density function (PDF) of error sequences of arbitrary length. From the joint PDF, we have found an analytical solution for the autocorrelation function (ACF) of the error sequences...
The synergetic integration of heterogeneous terrestrial and aerospace networks will play an important role in the evolution of wireless communications systems. In this direction, high-altitude platforms (HAPs) could act as relay stations in the stratosphere transferring information from an uplink to a downlink channel. This paper presents a novel transmission scheme for the delivery of mobile-to-mobile...
In this paper, we investigate opportunistic buffer-equipped, multi-antenna relay networks with a decode-and-forward relaying strategy. The channel that we are considering includes three key wireless channel effects: path loss, shadowing, and fast fading. We first analyze the direct communication outage probability, and based on that, analyze the opportunistic relay network's outage probability. For...
Traditional OFDM systems present some embedded features that may be exploited in order to intercept the wireless transmitted signal. However, such a possibility is not accepted in military applications where security is a very important issue. Cyclic prefix is one of the most obvious OFDM parameters that induce cyclostationarity features. Aiming to suppress these features, some classical solutions...
Temporal and spatial correlation are inherent mobile wireless channel characteristics that determine multiple-input multiple-output (MIMO) systems performance. It is widely known that in indoor laboratories with fixed conditions, wireless channels are intrinsically quasi-static. In this paper we propose a methodology for emulating multiple-input single-output (MISO) channels with arbitrary distributions...
In this paper, the channel capacity of a Multiple Input Multiple Output (MIMO) broadcast system is investigated under correlated fading environment where there exists a transmitter , a legitimate receiver and an eavesdrop, each node equipped with multiple antennas. We derive the secret capacity and its upper bound of the MIMO broadcast channel in detail by using the Information theory and random matrices...
Reliable spectrum sensing should be able to operate under realistic wireless environments such as multipath and fading. Based on the optimal spectrum sensing with multiple receiver antennas over multipath channels, this paper presents further studies into two more practical detection methods, the modified energy detection (MED) and the equal gain detection (EGD), over frequency-selective fading channels,...
In this paper, we consider multiantenna energy detection (ED) of nonnegative pulse-amplitude-modulated (PAM) symbols suitable for low-power and low-complexity short-range communication radios using a very wide bandwidth or high centre frequency. We present a general condition which leads to the cancellation of the spatial cross products between the distinct PAM space-time coded signals at the output...
This paper studies a spectrum sharing cognitive radio (CR) network coexisting with a primary network. In particular, the channel state information (CSI) between the secondary transmitter (STx) and the primary receiver (PRx) is assumed to be outdated due to channel feedback latency. We assume that the secondary user (SU) shall satisfy a given delay quality-of-service (QoS) constraint as well as the...
In this paper, we propose a novel complete two-dimensional shadow fading modeling on system level characterized by both spatial auto-correlation and site-to-site cross-correlation. Numerical results confirm that the proposed algorithm based on two-dimensional filter to generate shadowing auto-correlation is more approaching theoretical results comparing with the previous method, and the empirical...
Radio frequency (RF) chains are responsible for a large percentage of the total BS energy consumption and each RF chain can only support one activated transmit antenna at a time. This fact greatly benefits spatial modulation (SM) since at any given time instance only one antenna in an array is active. The proposed transmission optimised spatial modulation (TOSM) is an adaptive SM scheme which trades...
Frequency selective fading that is caused by the multipath becomes a problem in broad band communication like a UWB (Ultra Wideband) system. This paper discusses the RAKE reception technique by using the multicarrier template waveform in the UWB-IR (Impulse Radio) system to compensate the influence of multipath. The template waveform in the UWB receiver is modified to the multicarrier pulse, because...
Carrier aggregation (CA) has been proposed as a key feature of the 4G cellular networks to achieve the very high data rates. It is known that the correlation between the subchannels, including both small- and large-scale fading, is critical in determining the performance gain we can obtain from the multicarrier transmission. However, due to the prohibitively high complexity and cost in simultaneously...
Self-encoded spread spectrum (SESS) has been shown to provide significant advantages for communications in fading or jamming environments. With the proliferation of GNSS such as GPS, Galileo, and GLONASS, it would be desirable to bring the advantages of SESS to these systems. In order to do this the iterative detector in a receiver must be able to provide a high-quality timing estimate. Presented...
This paper presents second order statistical properties of the vehicle to vehicle Nakagami Hoyt (Nakagami-q) channel model under non-isotropic condition. The spatial-time correlation function, the power spectral density (PSD), level crossing rate (LCR) and the average fade duration (AFD) of the Nakagami Hoyt channel have been derived under the assumption that both the transmitter and receiver are...
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