Herbert Taylor

Two-dimensional synchronization patterns for minimum ambiguity

A number of closely related combinatorial problems corresponding to specific assumptions about the type of time-frequency sequence which may be appropriate in a particular application, are formulated in terms of square or rectangular arrays of dots with appropriate constraints on the two-dimensional correlation function. The current state of knowledge concerning each of these problems is summarized. It is hoped that more general constructions may be found, leading to larger families of solutions, as well as better computational algorithms for finding individual solutions which may lie outside of the general families.

Sonar sequences from Costas arrays and the best known sonar sequences with up to 100 symbols

The authors construct new and improved sonar sequences by applying rotation, multiplication, and shearing transformations to Costas sequence constructions. A catalog of the best known sonar sequences with up to 100 symbols is given. >

Acquisition sequences in PPM communications (Corresp.)

In pulse position modulation (PPM) communications an acquisition sequence is needed to establish frame synchronization for subsequent data transmission. This sequence must have PPM structure (one pulse per frame) and desirable autocorrelation properties for its detection. The problem of finding aperiodic PPM acquisition sequences having the minimum possible autocorrelation for all off-shifted positions is investigated. Sequences with the maximum possible number of frames have been found up to frame size 15 . Examples are given for every frame length up to 88 , and powers of two up to 1024 . An interesting relation between the PPM sequence problem, Costas and sonar arrays, and Golombs ruler is explored.

BOUNDS FOR ARRAYS OF DOTS WITH DISTINCT SLOPES OR LENGTHS

AbstractAnn×m sonar sequence is a subset of then×m grid with exactly one point in each column, such that the

Performance analysis of code division multiple access techniques in fiber optics with on-off and PPM pulsed signaling

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COLLECTING AUTOGRAṔHS: n‐NODE GRAPHS THAT HAVE n‐INTEGER SIGNATURES1

vectors determined by them are all distinct. We show that for fixedn the maximalm for which a sonar sequence exists satisfiesn−Cn11/20n+c logn log logn for infinitely manyn.Another problem concerns the maximal numberD of points that can be selected from then×m grid so that all the

Progressions in every two-coloration of Z n

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