We present a case of design and implementation of a high-speed burst QPSK (Quaternary Phase Shift Keying) receiver. Since the PSK modulation carries its information through the phase, the baseband digital receiver can recover transmitted symbol from the received phase. The implemented receiver estimates symbol time and frequency offset using sampled data over 32 symbols without transmitted symbol information, and embedded RAM is used for received phase delay over estimation time. The receiver is implemented using about 92,000 gates of Samsung KG75 SOG library which uses 0.65 µm CMOS technology. The fabricated chip test result shows that the receiver operates at 40 MHz clock rate on 5.6 V, which is equivalent to the 40 Mbps data rate.

This letter considers problems with an efficient link layer multicasting technique in a wireless personal area network environment using a directional antenna. First, we propose an adaptive directional multicast scheme (ADMS) for delay-sensitive applications in mmWave WPAN with directional antenna. Second, the proposed ADMS aims to improve throughput as well as satisfy the application-specific delay requirements. We evaluate the performances of legacy Medium Access Control, Life Centric Approach, and adaptive directional multicast schemes via QualNet 5.0. Our results show that the proposed scheme provides better performance in terms of total network throughput, average transmission time, packet delivery ratio and decodable frame ratio.

The generalized fading amplitude can be expressed using the Nakagami-m distribution. The probability density function (PDF) for the sum of m-distributions is needed to evaluate performance of diversity combining technique such as equal gain combining (EGC) receiver. The approximated PDF for the sum of m-distributions gives simpler performance expression and reduces the computational complexity in evaluating EGC performance. We investigate the normalized approximation error of EGC performance. From the observed result, even for m > 2, the approximated BER is not accurate. For example, the normalized error is about 32% for m = 2 with 3 identical and independently distributed (IID) fading branches and 10 dB SNR.

A dual management of real-time and interactive jobs in dual-core smartphones is presented. The proposed scheme guarantees the end-to-end QoS of real-time applications, while also provides reasonable latency for interactive applications. To this end, high performance NVRAM is adopted as storage of real-time applications, and a dual purpose CPU scheduler, in which one core is exclusively used for real-time applications, is proposed. Experiments show that the proposed scheme reduces the deadline miss ratio of real-time applications by 92%.

We present the approximated bit error rate (BER) performance of a binary phase shift keying (BPSK) modulated equal-gain combining (EGC) diversity receiver with phase noise over independent and non-identical Nakagami fading branches. The approximated BER becomes accurate with phase-locked loop (PLL) gain, K=20. Also, for special values of fading parameter, m, and branch number, L, we derived the closed form expression of the BER.