Fast acquisition of frame timing and frequency

A system, comprising:

• memory;
• and
• a receiver coupled to the memory, the receiver configured to:
• receive a signal comprising a framing property marked by a unique word (UW) comprising a predefined sequence of symbols;
• produce a digitally sampled signal corresponding to the received signal, the digitally sampled signal having a sampling rate of Na*Rs, wherein Rs is a symbol rate of the received signal and Na is a number of samples per symbol;
• determine a frequency offset associated with the received signal and a location of the unique word within a frame of the received signal, wherein the determining is based on a two-dimensional search and wherein the determining comprises:
• eliminating a unique word modulation from the digitally sampled signal to produce a plurality of vectors each having L un-modulated samples at intervals of 1/Rs, wherein L is a length, in symbols, of the unique word;
• counting the plurality of vectors using a first counter and associating each of the plurality of vectors with a time index corresponding to a count value of the first counter;
• summing groups of N adjacent samples within each of the plurality of vectors to produce decimated vectors of L/N samples, wherein N is a positive integer;
• padding the decimated vectors with time-domain zeroes to produce padded vectors of P*(L/N) samples, wherein P≧1;
• performing a Fourier Transform (FT) on the padded vectors to produce transformed vectors;
• counting FT samples of the transformed vectors using a second counter and associating each of the FT samples with a frequency index corresponding to a count value of the second counter;
• calculating at least one metric of magnitude for at least one sample in the transformed vectors;
• and
• storing the at least one metric of magnitude at a storage address in the memory, wherein the storage address is determined in accordance with the time index and the frequency index associated with the at least one sample corresponding to the at least one metric of magnitude.

A receiver, comprising:

• a means for receiving a signal comprising a framing property marked by a unique word (UW) comprising a predefined sequence of symbols;
• a means for producing a digitally sampled signal corresponding to the received signal, the digitally sampled signal having a sampling rate of Na*Rs, wherein Rs is a symbol rate of the received signal and Na is a number of samples per symbol;
• and
• a means for determining a frequency offset associated with the received signal and a location of the unique word within a frame of the received signal, wherein the determining is based on a two-dimensional search and wherein the determining comprises:
• eliminating a unique word modulation from the digitally sampled signal to produce a plurality of vectors each having L un-modulated samples at intervals of 1/Rs, wherein L is a length, in symbols, of the unique word;
• counting the plurality of vectors using a first counter and associating each of the plurality of vectors with a time index corresponding to a count value of the first counter;
• summing groups of N adjacent samples within each of the plurality of vectors to produce decimated vectors of L/N samples, wherein N is a positive integer;
• padding the decimated vectors with time-domain zeroes to produce padded vectors of P*(L/N) samples, wherein P≧1;
• performing a Fourier Transform (FT) on the padded vectors to produce transformed vectors;
• counting FT samples of the transformed vectors using a second counter and associating each of the FT samples with a frequency index corresponding to a count value of the second counter;
• calculating at least one metric of magnitude for at least one sample in the transformed vectors;
• and
• storing the at least one metric of magnitude at a storage address in a memory, wherein the storage address is determined in accordance with the time index and the frequency index associated with the at least one sample corresponding to the at least one metric of magnitude.