This paper proposes a game-theoretic random channel access model, compliant with the IEEE 802.11 standard that can be integrated into the distributed coordination function. The objective is to design a game theoretic model that can optimize both throughput and channel access delay in each node in the presence of hidden terminals and thus optimize fairness. We propose a utility function that can decouple the protocol's dynamic adaptation to channel load from collision detection. We demonstrate that our model can reach a Nash equilibrium resulting in a stable contention window, provided that a node adapts its behavior to the idle rate of the broadcast channel, coupled with observation of its own transmission activity. Simulation results show that this model is capable of achieving lower channel access delay and better throughput than the standard IEEE 802.11 distributed coordination function.

In recent years, speaker verification technologies have received an extensive amount of attention. Designing and developing machines that could communicate with humans is believed to be one of the primary motivations behind such developments. Speaker verification technologies apply to numerous fields such as security, Biometrics, and forensics. In this paper, the authors study the effects of different languages on the performance of the automatic speaker verification (ASV) system. The corpus used in this study is the MirasVoice speech corpus (MVSC). This corpus is a bilingual English and Farsi speech corpus. This study collects results from both an I-vector based ASV system and a GMM-UBM based ASV system. The experimental results show that a mismatch between the enrolled data used for training and verification data can lead to a significant decrease in overall system efficiency. This study shows that it is best to use an i-vector based framework with data from the English language used in the enrollment phase to improve the robustness of the ASV systems. Results collected in this study indicate that this can narrow the degradation gap caused by the language mismatch.

Wireless networking is fast becoming the primary method for people to connect to the Internet and with each other. The available wireless spectrum is increasingly congested, with users demanding higher performance and reliability from their wireless connections. This thesis proposes a game-theoretic random access model, compliant with the IEEE 802.11 standard, that can be integrated into the distributed coordination function (DCF). The objective is to design a game theoretic model that potentially optimizes throughput and fairness in each node independently and, therefore, minimise channel access delay. This dissertation presents a game-theoretic MAC layer implementation for single-cell networks and centralised DCF in the presence of hidden terminals to show how game theory can be applied to improve wireless performance. A utility function is proposed, such that it can decouple the protocol's dynamic adaptation to channel load from collision detection. It is demonstrated that the proposed model can reach a Nash equilibrium that results in a relatively stable contention window, provided that a node adapts its behaviour to the idle rate of the broadcast channel, coupled with observation of its own transmission activity.This dissertation shows that the proposed game-theoretic model is capable of achieving much higher throughput than the standard IEEE 802.11 DCF with better short-time fairness and signicant improvements in the channel access delay.To my parents and my sister

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