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.
Network coding in cooperative relaying can improve the performance of both users and provide improved efficiency as compared to the conventional relaying. This paper considers different detection schemes for cooperative relaying with network coding. Analytical upper bounds on the bit error probability are derived and used to assess the performance of the different schemes. The obtained results show...
This paper presents a physical and MAC layer analysis of the recently introduced IEEE 802.15.3c standard for multi Gbps communication at 60 GHz. We find the optimal beamwidth of the transmitting antenna, achieving a trade-off between the Piconet Coordinator discovery and the duration of the contention access period (CAP) of the IEEE 802.15.3c MAC superframe. To find the optimal beamwidth, we first...
This paper introduces an improved iterative soft decision subcarrier parallel interference cancellation (SDSub-PIC) technique for the carrier interferometry/multicarrier code division multiple access (CI/MC-CDMA) system that significantly reduces the multiple access interference (MAI) for the desired user. Carrier interferometry (CI) codes are used to minimize the cross-correlation between different...
The paper proposes a network coded cooperation protocol for the uplink transmission of relay assisted cellular networks characterized by non-ideal source - relay links. The proposed protocol employs Reed Solomon codes as network codes in order to improve the Block Error Rate (BLER) and Bit Error Rate (BER) performance over the slow varying fading channels. The paper presents also an algorithm for...
Coordinated multipoint (CoMP) transmission is being considered in next-generation cellular systems to improve cell-edge throughput. In this paper, we consider open-loop CoMP with L base stations (BSs) where they cooperatively serve a cell-edge user. We first propose antenna selected space-time block code (STBC) to exploit diversity gain for serving the cell-edge user and also support the scenario...
In this paper, a new space-frequency combination technique is proposed for Alamouti coded Orthogonal Frequency Division Multiplexing (OFDM) in the context of cooperative communications. Since cooperative antennas are distributed, there may exist multiple carrier frequency offsets (MCFOs) which cause problems for conventional space-frequency decoding. The proposed algorithm, taking cues from existing...
In this paper, we propose user grouping algorithms to provide power minimization in grouped STBC MC-CDMA systems. Depending on the channel fading conditions, power control is utilized to minimize the total transmitted power under a BER constraint. When the allocation is performed without a fair data rate requirement, we provide the optimal solution to the minimization problem. However when some fairness...
We consider in this paper relay assignment for cooperative systems with multiple two-way relay channels. The nodes corresponding to one two-way relay channel (henceforth referred to as pair) communicate with each other through a relay. The relays use network coding to simultaneously transmit the signals corresponding to the pairs they are assigned to. We propose two relay assignment schemes. One scheme...
In this paper, we propose a precoder using a minimum mean-square error (MMSE) criterion for a non-regenerative relay system. It is assumed that the relay knows the channel covariance information (CCI) of the relay-destination link and the full channel state information (CSI) of the source-relay link. We start by assuming the precoder has a specified structure. We derive an upper-bound of the mean-square...
In this paper, we undertake a comparison of LDPC (768,384) and convolutional (171,133) codes for 60-GHz OFDM-based wireless communication systems. The comparison is based on two parameters: Frame Error Rate (FER) for 60-GHz channels and decoding hardware complexity for a required throughput of more than 1 Gbps. Additionally, we provide performance parameters of a fully parallel LDPC decoder chip,...
This paper proposes and analyzes selection diversity as an effective tool to combat channel impairments in relay-assisted cellular systems. We consider the uplink scenario where the base station equipped with N antennas receives from the mobile station either directly, or indirectly via a relay station, according to the link with the strongest received signal-to-noise ratio (SNR). For this system,...
In this paper, performance of joint transmit and receive antenna selection in two hop amplify-and-forward relay system is analyzed over frequency non-selective and slowly Nakagami-m fading channels. In the system, all nodes are equipped with multiple antennas; Transmit Antenna Selection (TAS) is employed at the source and relay for transmission, Selection Combining (SC) is employed at the relay and...
A 60 GHz wireless Gigabit Ethernet (G.E.) communication system capable of near gigabit data rate has been developed at IETR. The realized system covers 2 GHz available bandwidth. This paper describes the design and realization of the overall system including the baseband (BB), intermediate frequency (IF) and radiofrequency (RF) blocks. A differential binary shift keying (DBPSK) modulation and a differential...
In the paper, a modified Log-MAP algorithm based on a novel approximation of the max* operator derived from the Jensen inequality is proposed. In this approach, the max* operation is performed on n≥2 arguments, thus the recursive calculations are avoided and significant reduction in the number of operations performed per decoding step, as compared with the conventional Log-MAP, is achieved. Simulation...
The recently allocated 71-76 GHz and 81-86 GHz bands provide an opportunity for Line Of Sight (LOS) links for directional point-to-point “last mile” links. An efficient use of this spectrum may allow wireless to finally “catch up” with wires, leading to systems such as “multi-Gigabit wireless Ethernet,” and “wireless fiber.” However, the transmission at such a frequency range is characterized by several...
Despite the very substantial body of research on the performance analysis of cooperative relay systems, most studies focus on either the symbol error ratio (SER) or outage behavior. This paper analyzes the asymptotic average packet error rate (PER) of the packet cooperative relay system for both AF (Amplify-and-Forward) and DF (Decode-and-Forward) schemes in the high signal-to-noise ratio (SNR) region,...
Distributed antenna systems (DASs) are expected to play an important role in the delivery of high data rates in future cellular networks. In DASs, the multipath fading and shadowing effects have to be analyzed concurrently due to the geographical scattering of the distributed antenna ports. The Gamma-Gamma (generalized-K) probability density function (PDF) has been adopted recently to model composite...
In orthogonal frequency division multiple access (OFDMA) systems, efficient resource allocation is very important to improve the performance of the OFDMA system. The general principle of resource allocation in an OFDMA system is to assign each subcarrier to the user with the best channel condition for that subcarrier. However, in delay tolerant traffic, current work did not consider that packets on...
This paper analyzes the end-to-end performance of the cooperative diversity wireless networks using the amplify-and-forward relaying and the selection combining receiver over independent Rayleigh fading channels. The performance analysis is presented in terms of the outage probability and the average bit error rate. Since it is hard to find exact closed form expressions for the outage probability...
Instead of using eigen-beamforming approach to increase capacity gain, an optimal weight scheme is employed in the closed-loop multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (MIMO-OFDM) wireless system design. In particular, this scheme provides an uplink scale weight vector pre-weighting space-time block code (STBC) signals at each transmit sub-carrier in accordance...
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.