The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this work, we examine the secrecy capacity region of the block-fading broadcast channel with confidential messages (BCC) when the transmitter has limited knowledge of the channel. In particular, we consider a two-user communication system where the transmitter has one common message to be transmitted to both users and one confidential message intended to only one of them. The confidential message...
We investigate the outage and decoding-delay performances for full-duplex (FD) decode-forward (DF) relaying with backward and sliding window decoding. In our analysis, we consider a block fading channel with full channel state information (CSI) availability at receivers and with limited CSI at transmitters. For backward decoding where the destination starts decoding from the last transmission block,...
Many aspects of lattice coding and decoding under time-varying multiple-antenna systems remain unexplored. This paper studies the achievable rates using lattice codes for the multiple-input- multiple-output (MIMO) point-to-point channel with ergodic fading and channel state information at the receiver. The proposed lattice coding scheme involves the use of decision regions that are universal for almost...
Caching of popular multimedia content at small-cell base stations (BSs) is a promising solution to reduce the traffic load of macro-BSs without relying on a high-speed backhaul architecture. While most prior work analyzed the effect of smallcell caching, or femto-caching, under the assumption of negligible interference between macro-BS and small-cell BS, this paper contributes to a more recent line...
Wireless communication systems use adaptive modulation and coding (AMC) as well as hybrid ARQ (HARQ) to mitigate the effects of time-varying and error-prone channels. In this work, we analyze the benefits of combining HARQ and AMC adopting the throughput as a unique performance measure. The analysis of block-fading channels and error-prone decoders allows us to conclude that i) adding HARQ on top...
A multiple-input-multiple-output (MIMO) version of Costa's dirty paper channel is studied, where both the input signal and the state experience ergodic fading with channel state information at the receiver. An inner bound using lattice coding and decoding is derived and its gap to the point-to- point ergodic capacity is computed. Under Rayleigh fading, the gap is a constant that vanishes as the number...
We propose a new linear physical-layer network coding and information combining scheme for the K-user fading multiple-access relay network (MARN), which consists of K users, one relay and one destination. The relay and the destination are connected via a rate-constraint backhaul link. In the proposed scheme, the K users transmit signals simultaneously. The relay and the destination receive the superimposed...
One of the most important solutions for spectrum shortage, expected by 2020, is wireless networks with super density, which is also expected to provide significant economic impacts. This paper proposes decoding scheme with practical analysis for massive number of users in super-dense wireless networks involving two multiway relays (SD-MWMR). The practicality is viewed from the point of finite-length...
In this paper, a new cooperative spectrum sharing protocol that employs space-time block coded spatial modulation (STBC-SM) at the secondary user (SU), is proposed for overlay cognitive radio (CR) networks. STBC-SM is applied at the secondary transmitter (ST) which transmits its data by both modulated symbols and antenna combinations while conveying PU's data only by modulated symbols. This protocol...
In this paper, we consider a cognitive two-way relay system with multiple relay nodes and multiple primary receivers over Nakagami-m fading channels. Relay nodes process signal following selective decode-and-forward (DF) relay technique. The opportunistic relay selection is used to choose the best relay. We derive the exact closed-form expression of the overall outage probability over Nakagami-m fading...
In this paper, a down-link cooperative communication scheme is proposed using full-rate Quasi-Orthogonal Space-time Block Codes (QOSTBC), employing asynchronous mobile Decode and Forward (DF) relays in a Rayleigh fading wireless environment. The channel used is a partially-coherent relay channel (PCRC), where the first hop is non-coherent and the second is coherent. Base station broadcasts using four...
In this paper, we investigate the problem of secure broadcasting over block-fading channels with limited channel knowledge at the transmitter. More particularly, we analyze the effect of having imperfect channel state information (CSI) via a finite rate feedback on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper...
In this paper, we investigate the secrecy performance of multiuser dual-hop relay networks where a base station (BS) communicates with multiple legitimate users via the assistance of a trustful regenerative relay in the presence of multiple eavesdroppers. In particular, the maximal ratio transmission (MRT) scheme is exploited at the BS and a threshold-based multiuser scheduling scheme is employed...
In this work, we propose a new technique of spatially-coupled low-density parity-check coding within a threshold-based lossy forwarding protocol for a multiple access relaying system. Here, block Rayleigh fading is assumed for all transmission links and error-free decoding at the relay is not required. Two schemes are presented in which the relay computes log-likelihood ratios (LLRs) of the network-coded...
3G systems, which are expected to still be widely deployed over the next decade, utilize Direct-Sequence Code-Division Multiple-Access (DS-CDMA) which suffers mainly from the Multiple Access Interference (MAI). This paper proposes improved decoder log-likelihood ratios for the practical uplink. The basic idea is to utilize knowledge about user cross-correlations and fading coefficients to obtain conditional...
There has been a rejuvenated interest in the use of arbitrary constellations (non-equally spaced) after promising performance results were demonstrated compared to conventional grid and circular constellations. To enable the development of such constellations, in this contribution we derive an upper bound bit-error-rate (BER) expressions for coded transmit maximum ratio combining (TMRC) systems operating...
We consider the problem of sending a bivariate Gaussian source over a slow-fading multiple-access channel (MAC) with no channel state information at the transmitters. A joint source-channel coding (JSCC) scheme is constructed using hybrid digital- analog (HDA) coding techniques to minimize the average distortion over the uncertain MAC. Numerical results show that, under Rayleigh fading, the proposed...
This paper analyzes a novel multiple-input single- output (MISO) simultaneous wireless information and power transfer (SWIPT) system model in the presence of an active eavesdropper over the frequency-selective fading channel. In this model, a transmitter applies the time reversal (TR) beamforming technique to combat the fading effects whereas a legitimate user employs a power splitter to jointly receive...
In this work, we evaluate the performance of Wavelet-Coding into offering robustness for OFDM signals against the combined effects of varying fading and noise bursts. Wavelet-Code enables high diversity gains with a low complex receiver, and, most notably, without compromising the system's spectral efficiency. The results show that the Wavelet-Coded OFDM system achieves a BER of 1E-3 with nearly 6...
In this paper, we investigate the resource allocation problem for the downlink non-orthogonal multiple access (NOMA) system with imperfect channel state information (CSI). We first derive closed-form expressions for the outage probabilities with and without the estimated instantaneous channel fading coefficient for each user. Upper bounds on both of the probability expressions above are proposed....
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.