Kar-Peo Yar

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In this work, we use an analytical method developed in S.Y. Chang et al (2004) to determine the joint distribution of the energy and delay of a transmitted data packet for wireless networks utilizing the IEEE 802.11 standard for medium access control. Our analysis takes into account the effect of the channel noise on the transmission of the RTS, CTS, data,(More)
This paper explores multiuser downlink beamforming in a distributed manner, where each user locally and sequentially optimizes its own beamforming phase and amplitude according to some performance measures. For phase optimization, the complex non-convex optimization problem is reformulated into a convex one. Given the optimal phase, the amplitude is pursued(More)
Frequency-selective fading and inter-carrier-interference (ICI) are two fundamental issues that should be dealt with before adopting orthogonal frequency division multiplexing (OFDM). Instead of using complex designs for exploiting frequency diversity and cancelling ICI, this paper explores how spreading signal, on either frequency-domain or time-domain,(More)
In this paper we analyze the average delay and total energy consumption of a hybrid automatic repeat request (ARQ) system taking into account the energy of the transmitter and receiver. We use the random coding bound and cutoff rate in our analysis. We demonstrate that there is an optimum code rate that achieves the minimum delay and energy consumed. To(More)
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