Frame synchronization with unique-word dependent filter coefficients

A method for detection of a unique word in a bit stream, comprising the actions of:

• (a.) repeatedly testing to detect a near match between said incoming bit stream and a set of stored coefficients;
• wherein said stored coefficients vary in dependence on the specific value of said unique word, and are not equal to said unique word nor to any shift or multiple thereof;
• and
• (b.) detecting said unique word in said bit stream whenever said step (a.) detects a near match.

A method for receiving synchronous communication, in a format where a unique word, which is normally preceded by a synchronization pattern, marks frame boundaries in a data stream, comprising the actions of:

• (a.) feeding the data stream into a finite impulse response filter structure which applies a coefficient vector to derive a receiver output signal from said data stream, said coefficient vector
• having more than binary resolution, and
• being dependent on the specific value:
• of the unique word, and lying within the space spanned by a collection of vectors Vi, and being near said vectors Vi;
• wherein each said vector Vi represents the difference between said unique word and a respective candidate vector Si which is a subsequence taken from the concatenation of said unique word with said synchronization pattern;
• and
• (b.) detecting a frame boundary in said:
• bit stream whenever said step (a.) produces a receiver output signal which is above a threshold;
• and
• (c.) extracting data from said bit stream at only some offsets from the frame boundary detected in said step (b.).

A receiving method for synchronous communication, comprising the actions of:

• (a.) repeatedly testing to detect a near match between an incoming bit stream and a set of stored coefficients;
• wherein said stored coefficients vary in dependence on the specific value of a unique word which marks the timing of a frame boundary, and are not equal to said unique word nor to any bit rotation thereof;
• (b.) detecting a frame boundary in said bit stream whenever said step (a.) detects a near match;
• and
• (c.) extracting data from said bit stream at only some offsets from the frame boundary detected in said step (b.).

A time-domain-segmented communication system, comprising:

• a transmitter which transmits a bit stream which is formatted in frames of data;
• and
• a receiver which performs the actions of:
• (a.) repeatedly testing to detect a near match between an incoming bit stream and a set of stored coefficients;
• wherein said stored coefficients vary in dependence on the specific value of a unique word which marks the timing of a frame boundary, and are not equal to said unique word nor to any bit rotation thereof;
• (b.) detecting a frame boundary in said bit stream whenever said step (a.) detects a near match;
• and
• (c.) extracting data from said bit stream at only some offsets from the frame boundary detected in said step (b.).

A portable telephone system, comprising:

• a wireless receiver, and digitizing stages which provide a digital bit stream as output in dependence on signals received by said receiver;
• and
• at least one signal processing stage receiver which is connected to receive said bit stream, and which performs the actions of:
• (a.) repeatedly testing to detect a near match between said bit stream and a set of stored coefficients;
• wherein said stored coefficients vary in dependence on the specific value of a unique word which marks the timing of a frame boundary, and are not equal to said unique word nor to any bit rotation thereof;
• (b.) detecting a frame boundary in said bit stream whenever said step (a.) detects a near match;
• and
• (c.) extracting data from said bit stream at only some offsets from the frame boundary detected in said step (b.).