# Accession Number:

## AD0726101

# Title:

## Subsequence Sync Design.

# Descriptive Note:

## Final technical rept. Mar-Nov 70,

# Corporate Author:

## RAYTHEON CO SUDBURY MASS EQUIPMENT DIV

# Personal Author(s):

# Report Date:

## 1971-06-01

# Pagination or Media Count:

## 49.0

# Abstract:

The report is concerned with the determination of the phase of a binary sequence whose rule of formation is known but which has been received with errors. It is desired to determine the phase from a relatively short sequence. The authors describe what they call a predictive correlator, which represents a new approach to the correlation problem. It allows decisions on the phase of the incoming sequence in a much shorter tme and with much simpler equipment than a conventional correlator, with better probability of success. Although the emphasis is on the m-sequences the idea is applicable to any binary sequence. The authors present the design of a predictive correlator, which would operate at a 10 nanosecond rate, and of all equipment which would be necessary for a laboratory demonstration of the feasibility of the scheme. In addition, the report discusses some results on the statistics of the weights of subsequences of an m-sequence. It is shown that the predictive correlator will provide synchronization on subsequences of length 500 for an m-sequence of length 2 to the 23rd power-1 with probability of missed synchronization and false synchronization more than two orders of magnitude less than the probability of error of the input pulses. Author

# Descriptors:

# Subject Categories:

- Cybernetics
- Non-Radio Communications