Orthogonal Frequency-Division Multiple Access (OFDMA) systems have attracted considerable attention through technologies such as 3GPP Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX). OFDMA is a flexible multiple-access technique that can accommodate many users with widely varying applications, data rates, and Quality of Service (QoS) requirements. OFDMA has...

Although division is less frequent than addition and multiplication, because of its longer latency it dissipates a substantial part of the energy in floating-point units. In this paper we explore the relation between the radix and the energy dissipated. Previous work has been done on radix-4 and radix-8 division. Here we extend this study to a radix16 scheme with two overlapped radix-4 stages a...

In a fast fading channel, the orthogonality of the two consecutive Space Time Block Codes (STBC)-Orthogonal Frequency Division Multiplexing ( OFDM) symbols will be destroyed and the received signals cannot be perfectly separated. TR(Tone Reservation) is a technique designed to combat this problem by reserving a number of carries(tone) in the frequency domain to generate a cancellation signal in...

Let k be an algebraically closed field of characteristic 0 and let D be a division algebra whose center F contains k. We shall say that D can be reduced to r parameters if we can write D ≃ D0 ⊗F 0 F , where D0 is a division algebra, the center F0 of D0 contains k and trdeg k (F0) = r. We show that every division algebra of odd degree n ≥ 5 can be reduced to ≤ 1 2 (n − 1)(n − 2) parameters. More...

This paper presents a mixed method for reducing order of the large scale interval systems using the Mihailov Criterion and factor division method. The denominator coefficients of reduced order model is determined by using Mihailov Criterion and numerator coefficients are obtained by using Factor division method. The mixed methods are simple and guarantee the stability of the reduced model if th...

Recent development in data communication applications, the role of Orthogonal Frequency Division Multiplexing (FDM) technology is unavoidable. The OFDM system improves the multipath fading channel and bandwidth in effective manner. But the main problem in OFDM is large fluctuations. This often affected the design performance and produces the poor results when compared to the existing methodolog...