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.

Rate-based adaptive congestion control system and method for integrated packet networks

Abstract: An adaptive congestion control device (600) and method provides for minimizing congestion on a basis of independent congestion level indicators (626). The invention further provides efficient recovery in an integrated packet network (17, 26, 32, 38) that becomes congested. In addition, the invention ensures that a user may utilize the network on a space-available basis when capacity is available in the network.

Device and method for on-line adaptive selection of baud rate and carrier frequency

Abstract: Optimal baud rate and carrier frequency for data transmission using a modem on a communication channel (100) are determined by utilizing an on-line line probing technique. The technique utilizing the information from a decoder noise power spectrum estimated from the equalized received modulated signals and decoder output symbols to determine the decoder signal-to-noise ratios (SNRs) and supported bit rates for the available baud rates and carrier frequencies. These SNRs and bit rates together with a band edge SNR difference at each frequency band are utilized to select (110) the optimal baud rate and carrier frequency.

Resynch Procedures and a Fail-Safe Network Protocol

Abstract: In this paper a new class of network synchronization procedures, called Resynch Procedures, is described. A resynch procedure is a mechanism for effectively bringing all nodes of a distributed network to a known state simultaneously, despite arbitrary finite delays between nodes. The procedures presented have the interesting property that no time-outs are required. One use of a resynch procedure is to implement a network protocol that can guarantee that no packets will be lost and no duplicate packets will be inadvertently received, despite arbitrary node and link failures. This appears to be the first demonstration that such fail-safe protocols exist.

Numerically robust least-squares lattice-ladder algorithms with direct updating of the reflection coefficients

Abstract: New time-recursive equations are derived for the reflection coefficients and the ladder gains in the a priori and a posteriori forms of the exact least-squares (LS) lattice-ladder filtering algorithms. The numerical accuracy of the LS lattice-ladder algorithms obtained by use of these new direct time update equations is analyzed and compared to the accuracy resulting from the conventional LS lattice-ladder algorithms. The analysis and a number of simulation results which are presented lead us to conclude that the new a priori and a posteriori forms of the LS lattice-ladder algorithms yield superior performance.

Convolutional codes III. Sequential decoding

Abstract: Sequential decoding is characterized as a sequential search for the shortest path through a trellis. An easily analyzed algorithm closely related to the stack and Fano algorithms is described. Martingale techniques are used to find the distribution of computation on totally symmetric channels. For general channels, our universal bounding technique yields the well-known Pareto distribution of computation, as well as a bound on error probability that is asymptotically optimum in the high-rate range. The performance-complexity relation is shown to be asymptotically Pareto for both sequential and maximum-likelihood (Viterbi) decoding, with the same exponent in either case. A semisequential list-of-L Viterbi algorithm is introduced to extend the analogies below Rcomp.