Codex Corporation

About: Codex Corporation is a based out in . It is known for research contribution in the topics: Network packet & Signal. The organization has 189 authors who have published 241 publications receiving 32205 citations.

Convergence and steady state behavior of a phase-splitting fractionally spaced equalizer

Abstract: The eigenstructure, initial convergence, and steady-state behavior of a phase-splitting fractionally spaced equalizer (PS-FSE) are analyzed. It is shown that the initial convergence rate of a T/3, or in general a T/M, PS-FSE using the least-mean-square (LMS) stochastic gradient adaptive algorithm is half that of a symbol rate equalizer (SRE) or a complex fractionally spaced equalizer (CFSE) with the same time span. The authors also show that the LMS adaptive PS-FSE with symbol rate update converges to a Hilbert transformer followed by a matched filter in cascade with an optimal SRE and thus forms an optimal receiver structure. >

A rapid acquisition of PN sequences for DS/SS systems based on a truncated SPRT

Abstract: The authors study a rapid coherent acquisition scheme, using a truncated sequential-probability-ratio test (TSPRT), for direct-sequence-spread spectrum (DS/SS) systems. Since the partial correlation of pseudonoise (PN) sequences is difficult to characterize, the worst-case partial correlation is considered. Linearized bounds of the partial correlation are used for designing the TSPRT so that the resulting test can achieve the prescribed acquisition condition. The design parameters of the TSPRT are chosen so that the average sample size (ASN) is minimized while keeping the maximum ASN smaller than that of the fixed dwell scheme with similar false alarm and miss probabilities. Some simulation results are obtained, and they agree well with analytic results. >

Channel reuse multiple access protocol for bidirectional bus networks

Abstract: A novel contention-free multiple-access protocol for bidirectional-passive bus packet networks is proposed. One version has a simple fixed-assignment transmission scheduling similar to that of the time-division multiple-access protocol, except that left-going and right-going packets may be transmitted only in alternate rounds. Another version employs a simple reservation scheme to provide demand-assignment transmission scheduling. In either instance the protocol may offer a maximum throughput exceeding one packet per packet transmission time under appropriate conditions, where throughput is defined as the number of distinct packets transmitted successfully per packet transmission time. This is possible through channel reuse as explained. >