No abstract

Abstract-A new base station receiver is proposed and analyzed for a code-division multiple-access (CDMA) cellular system. The proposed receiver can achieve remarkable diversity gain by increasing diversity order with reasonable cost and complexity. From the numerical results, it is confirmed that the proposed receiver structure can be a practical solution for enhancing reverse-link capacity and improving performance in CDMA cellular system operations. The result in the letter can find its applications to legacy IS-95/cdma2000 1x base stations with simple modifications.Index Terms-Code-division multiple access (CDMA), diversity, multipath fading, receiver complexity.

As state-of-the-art mobile devices are demanded for high performance and attractive designs, system-on-chips have been integrated with many functional blocks into a single chip to reduce the chip size, cost, and power consumption. In this paper, to reduce power consumption of heterogeneous processor, a power management algorithm is proposed with a time-based power control architecture which autonomously performs voltage/clock scaling operations without the intervention of the processors. The proposed algorithm has adaptively adjusted time-threshold levels for voltage/clock control to minimize the power consumption and work in severe time-constraints for real-time processing. The real-time adjustment makes robust performance of the power consumption guarantee regardless of patterns of data traffic and diverse application programs. To show performance of the proposed, they are adopted to an application processor integrated with a communication processor for smartphones. Via electronic system-level simulation, it is shown that the proposed algorithm reduces the power consumption by approximately 40%.

In this paper, we devise and comprehensively analyze an efficient transmission protocol for multiple half-duplex relay communication without a direct link but with inter-relay interference. The proposed protocol achieves high diversity gain with the help of Hybrid Automatic Retransmission reQuest (H-ARQ) even when multiplexing gain is quite high. As the maximum allowable number of retransmission rounds (L) increases, an additional time diversity gain is obtained in short-term static channels. Compared to pre-existing protocols which adopt H-ARQ in a similar manner, its diversity gain at high multiplexing gain is much improved. As L increases, the dominating region become wider. In addition, in long-term static channels, we show that more than two retransmissions (i.e., L > 2) are unnecessary for improvement of the diversity gain.

No abstract