Systems and methods for synchronization by transceivers with OQPSK demodulation

A demodulator for processing an analog signal, the demodulator comprising:

• a correlation result generator configured to receive an analog signal and generate a stream of correlation results based at least in part on the analog signal, the stream of correlation results including a first plurality of correlation results, a second plurality of correlation results, and a third plurality of correlation results, the first plurality of correlation results being different from the second plurality of correlation results by at least one correlation result, the second plurality of correlation results being different from the third plurality of correlation results by at least another correlation result;
• a first storage configured to receive the stream of correlation results and including N storage units, N being a variable based on a frequency of the analog signal, such that N changes with the frequency of the analog signal being changed;
• an adder coupled to the correlation result generator and configured to receive first selected correlation results of the first plurality of correlation results and determine a first sum of the first selected correlation results, receive second selected correlation results of the second plurality of correlation results and determine a second sum of the second selected correlation results, and receive third selected correlation results of the third plurality of correlation results and determine a third sum of the third selected correlation results;
• a symbol synchronization selector coupled to the adder and configured to compare the first sum, the second sum, and the third sum and to determine a point of symbol synchronization based at least in part on the first sum, the second sum and the third sum;
• and
• a symbol decoder;
• wherein the symbol synchronization selector is further configured to, if the second sum is larger than the first sum and the third sum,
• determine the second sum being a present peak corresponding to a present peak time;
• and
• search for a next peak within a time window;
• wherein:
• the time window starts at a beginning time and ends at an end time;
• the beginning time follows the present peak time by a first predetermined time duration;
• and
• the end time follows the beginning time by a second predetermined time duration;
• wherein the symbol decoder is configured to:
• receive the point of symbol synchronization;
• and
• decode the analog signal based at least in part on the point of symbol synchronization.

A demodulator for processing an analog signal, the demodulator comprising:

• a correlation result generator configured to receive an analog signal and generate a stream of correlation results based at least in part on the analog signal, the stream of correlation results including a first plurality of correlation results, a second plurality of correlation results, and a third plurality of correlation results, the first plurality of correlation results being different from the second plurality of correlation results by at least one correlation result, the second plurality of correlation results being different from the third plurality of correlation results by at least another correlation result;
• a first storage configured to receive the stream of correlation results and including N storage units, N being a variable based on a frequency of the analog signal, such that N changes with the frequency of the analog signal being changed;
• an adder coupled to the correlation result generator and configured to receive first selected correlation results of the first plurality of correlation results and determine a first sum of the first selected correlation results, receive second selected correlation results of the second plurality of correlation results and determine a second sum of the second selected correlation results, and receive third selected correlation results of the third plurality of correlation results and determine a third sum of the third selected correlation results;
• a symbol synchronization selector coupled to the adder and configured to determine a point of symbol synchronization;
• and
• a symbol decoder;
• wherein the symbol synchronization selector is further configured to:
• determine a present peak corresponding to a present peak time and corresponding to a first value of a peak count;
• and
• compare the first sum, the second sum, and the third sum;
• wherein the symbol synchronization selector is further configured to,
• if the second sum is not larger than the first sum or the third sum or is not larger than the first sum and the third sum,
• determine whether the first value is equal to a first predetermined value;
• if the second sum is larger than the first sum and the third sum,
• set the second sum to be a next peak corresponding to a next peak time;
• determine whether the next peak is larger than the present peak;
• and
• if the next peak is not larger than the present peak, determine whether the first value is equal to the first predetermined value;
• wherein the symbol decoder is configured to:
• receive the point of symbol synchronization;
• and
• decode the analog signal based at least in part on the point of symbol synchronization.

A method for processing an analog signal, the method comprising:

• receiving an analog signal;
• generating a digital signal based at least in part on the analog signal;
• processing information associated with the digital signal;
• generating a stream of correlation results based on at least information associated with the digital signal, the stream of correlation results including a first plurality of correlation results, a second plurality of correlation results, and a third plurality of correlation results, the first plurality of correlation results being different from the second plurality of correlation results by at least one correlation result, the second plurality of correlation results being different from the third plurality of correlation results by at least another correlation result;
• storing the stream of correlation results in a storage including N storage units, N being a variable based on a frequency of the analog signal, such that N changes with the frequency of the analog signal being changed;
• receiving first selected correlation results of the first plurality of correlation results;
• determining a first sum of the first selected correlation results;
• receiving second selected correlation results of the second plurality of correlation results;
• determining a second sum of the second selected correlation results;
• receiving third selected correlation results of the third plurality of correlation results;
• determining a third sum of the third selected correlation results;
• receiving and storing the first sum at a first time;
• receiving and storing the second sum at a second time, the second time following the first time;
• receiving and storing the third sum at a third time, the third time following the second time;
• processing information associated with the first sum, the second sum, and the third sum;
• determining a point of symbol synchronization based at least in part on the first sum, the second sum and the third sum;
• and
• decoding the analog signal based at least in part on the point of symbol synchronization.

A method for processing an analog signal, the method comprising:

• receiving an analog signal;
• generating a stream of correlation results based at least in part on the analog signal, the stream of correlation results including a first plurality of correlation results, a second plurality of correlation results, and a third plurality of correlation results, the first plurality of correlation results being different from the second plurality of correlation results by at least one correlation result, the second plurality of correlation results being different from the third plurality of correlation results by at least another correlation result;
• storing the stream of correlation results in a storage including N storage units, N being a variable based on a frequency of the analog signal, such that N changes with the frequency of the analog signal being changed;
• receiving first selected correlation results of the first plurality of correlation results;
• determining a first sum of the first selected correlation results;
• receiving second selected correlation results of the second plurality of correlation results;
• determining a second sum of the second selected correlation results;
• receiving third selected correlation results of the third plurality of correlation results;
• determining a third sum of the third selected correlation results;
• comparing the first sum, the second sum, and the third sum;
• determining a point of symbol synchronization based at least in part on the first sum, the second sum and the third sum;
• and
• decoding the analog signal based at least in part on the point of symbol synchronization;
• wherein the determining a point of symbol synchronization based at least in part on the first sum, the second sum and the third sum includes:
• if the second sum is larger than the first sum and the third sum,
• determining the second sum being a present peak corresponding to a present peak time;
• and
• searching for a next peak within a time window;
• wherein:
• the time window starts at a beginning time and ends at an end time;
• the beginning time follows the present peak time by a first predetermined time duration;
• and
• the end time follows the beginning time by a second predetermined time duration.

A method for processing an analog signal, the method comprising:

• receiving an analog signal;
• generating a stream of correlation results based at least in part on the analog signal, the stream of correlation results including a first plurality of correlation results, a second plurality of correlation results, and a third plurality of correlation results, the first plurality of correlation results being different from the second plurality of correlation results by at least one correlation result, the second plurality of correlation results being different from the third plurality of correlation results by at least another correlation result;
• storing the stream of correlation results in a storage including N storage units, N being a variable based on a frequency of the analog signal, such that N changes with the frequency of the analog signal being changed;
• receiving first selected correlation results of the first plurality of correlation results;
• determining a first sum of the first selected correlation results;
• receiving second selected correlation results of the second plurality of correlation results;
• determining a second sum of the second selected correlation results;
• receiving third selected correlation results of the third plurality of correlation results;
• determining a third sum of the third selected correlation results;
• processing information associated with the first sum, the second sum, and the third sum;
• determining a point of symbol synchronization;
• and
• decoding the analog signal based at least in part on the point of symbol synchronization;
• wherein the determining a point of symbol synchronization includes:
• determining a present peak corresponding to a present peak time and corresponding to a first value of a peak count;
• comparing the first sum, the second sum, and the third sum;
• if the second sum is not larger than the first sum or the third sum or is not larger than the first sum and the third sum, determining whether the first value is equal to a first predetermined value;
• and
• if the second sum is larger than the first sum and the third sum,
• setting the second sum to be a next peak corresponding to a next peak time;
• determining whether the next peak is larger than the present peak;
• and
• if the next peak is not larger than the present peak, determining whether the first value is equal to the first predetermined value.