By reusing the cellular resources, device-to-device (D2D) communication is becoming a very promising technology that greatly enhances the spectrum utilization. To harvest the benefits that D2D communications can offer, efficient resource allocation strategy is required to guarantee the demands of quality of service (QoS) for both cellular and D2D users. This paper proposes a resource allocation...

An orthogonal decomposition of a general wideband space-time multipath channel is derived assuming antenna arrays at both the transmitter and receiver. Knowledge of channel state information is assumed at both the transmitter and receiver. The decomposition provides a framework for efficiently managing the degrees of freedom in the space-time channel to optimize any combination of bit-error rat...

Rate adaptation and transmission power control in 802.11 WLANs have received a lot of attention from the research community, with most of the proposals aiming at maximising throughput based on network conditions. Considering energy consumption, an implicit assumption is that optimality in throughput implies optimality in energy efficiency, but this assumption has been recently put into question...

It is well known that in IEEE 802.11 networks, the assignment of low-rate and high-rate users to the same access point significantly degrades the performance of the high-rate users. Our objective is to investigate the implications of the above performance degradation on the incentives for handover between 802.11 wireless local area networks with overlapping coverage. Our focus is on the incenti...

We analyze the opportunistic relaying based on hybrid automatic repeat request (HARQ) transmission over the block-fading channel with absence of channel state information (CSI) at the transmitter nodes. We assume that both the source and the relay are allowed to vary their transmission rate between the HARQ transmission rounds. We solve the problem of throughput maximization with respect to the...

With the explosive growth of multimedia services in today’s wireless communications, this paper addresses the Quality of Service (QoS) issue focusing on satisfying the throughput requirement for real-time multimedia applications. An Adaptive Transmission Opportunity (AD-TXOP) scheme for a distributed Wireless Local Area Network (WLAN) system based on IEEE 802.11e Enhanced Distributed Channel Ac...

In this paper, a type-I hybrid SR ARQ scheme using trellis coded modulation (TCM) for point-tomultipoint communication was analyzed on nonstationary broadcast channels where the channel bit error rate (BER) varies over time. A nonstationary channel is modelled as a two-state Markov chain. In the numerical calculations, it is found that, for a given p 1 and ε̄ , the values of the average burst le...

Random Early Detection (RED) is one of the most commonly used Active Queue Management (AQM) algorithms that is recommended by IETF for deployment in the network. Although RED provides low average queuing delay and high throughput at the same time, but effectiveness of RED is highly sensitive to the RED parameters setting. As network condition varies largely, setting RED's parameters with fixed ...

The increasing usage of 3G CDMA systems has led to many developments aimed at improving the system efficiency. The HSDPA feature of the Wideband CDMA improves the system efficiency by sharing the base station resources among several users. It employs a common downlink channel having shorter sub-frames which can be allocated to users dynamically. This report presents a scheduling policy for a si...