Pulse radio receiver

A pulse waveform receiving apparatus comprising:

• a reference waveform generation section that generates a reference waveform signal;
• a delay section that generates a plurality of delayed waveform signals by delaying the reference waveform signal by different amounts of delay;
• a correlation calculation section that generates a plurality of correlation values comprising a correlation value between a received signal and the reference waveform signal and a correlation value between the received signal and each of the plurality of delayed waveform signals;
• a determination section that compares the plurality of correlation values in a combination comprising the correlation values which are not adjacent to each other in a time domain, and generates a difference detection signal showing a direction and degree of a phase shift between the received signal and the reference waveform signal according to comparison results;
• and a synchronization control section that controls a phase of the reference waveform signal generated by the reference waveform generation section based on the difference detection signal, wherein, for combinations of the correlation values, the determination section is configured to:
• use, for a third combination, a first correlation value calculated using the reference waveform signal and a third correlation value calculated using one of the plurality of delayed waveform signals other than a delayed waveform signal with a greatest amount of delay in the delayed waveform signals;
• use, for a fourth combination, a second correlation value calculated using the delayed waveform signal with the greatest amount of delay and a fourth correlation value calculated using one of the plurality of delayed waveform signals other than the delayed waveform signal with the greatest amount of delay in the delayed waveform signals;
• use, for a fifth combination, the first correlation value and a fifth correlation value calculated using one delayed waveform signal which is other than the delayed waveform signal with the greatest amount of delay in the plurality of delayed waveform signals and which is different from the delayed waveform signal used to calculate the third correlation value or the fourth correlation value;
• uses, for a sixth combination, the second correlation value and the fifth correlation value;
• calculates a third evaluation value by subtracting a value obtained by subtracting the first correlation value from the third correlation value in the third combination, from a value obtained by subtracting the second correlation value from the fifth correlation value in the sixth combination;
• calculate a fourth evaluation value by subtracting a value obtained by subtracting the second correlation value from the fourth correlation value in the fourth combination, from a value obtained by subtracting the first correlation value from the fifth correlation value in the fifth combination;
• and further generates the difference detection signal based on a relative scale between the third evaluation value and the fourth evaluation value.

A pulse waveform receiving apparatus comprising:

• a reference waveform generation section that generates a reference waveform signal;
• a delay section that generates a plurality of delayed waveform signals by delaying the reference waveform signal by different amounts of delay;
• a correlation calculation section that generates a plurality of correlation values comprising a correlation value between a received signal and the reference waveform signal and a correlation value between the received signal and each of the plurality of delayed waveform signals;
• a determination section that compares the plurality of correlation values in a combination comprising the correlation values which are not adjacent to each other in a time domain, and generates a difference detection signal showing a direction and degree of a phase shift between the received signal and the reference waveform signal according to comparison results;
• and a synchronization control section that controls a phase of the reference waveform signal generated by the reference waveform generation section based on the difference detection signal, wherein the determination section generates a plurality of combined signals by combining the correlation values in the combinations, equalizes each of the combined signals and adds and combines the equalized combined signals to generate the difference detection signal, and wherein, for the combination of the correlation values, the determination section is configured to:
• use, for a first combination, a first correlation value calculated using the reference waveform signal and a third correlation value calculated using one of the plurality of delayed waveform signals other than a delayed waveform signal with a greatest amount of delay in the delayed waveform signals;
• use, for a second combination, a second correlation value calculated using the delayed waveform signal with the greatest amount of delay and a fourth correlation value calculated using one delayed waveform signal other than the signal with the greatest amount of delay in the plurality of delayed waveform signals;
• and generate the difference detection signal based on a relative scale between a first evaluation value obtained by subtracting the first correlation value from the third correlation value in the first combination and a second evaluation value obtained by subtracting the second correlation value from the fourth correlation value.

A pulse waveform receiving apparatus comprising:

• a reference waveform generation section that generates a reference waveform signal;
• a delay section that generates a plurality of delayed waveform signals by delaying the reference waveform signal by different amounts of delay;
• a correlation calculation section that generates a plurality of correlation values comprising a correlation value between a received signal and the reference waveform signal and a correlation value between the received signal and each of the plurality of delayed waveform signals;
• a determination section that compares the plurality of correlation values in a combination comprising the correlation values which are not adjacent to each other in a time domain, and generates a difference detection signal showing a direction and degree of a phase shift between the received signal and the reference waveform signal according to comparison results;
• and a synchronization control section that controls a phase of the reference waveform signal generated by the reference waveform generation section based on the difference detection signal, wherein:
• the determination section being further configured to perform a logical AND operation that generates a pulse correlation detection signal showing whether or not the received signal is caught, based on a relative scale between combinations of the correlation values shown by the correlation values;
• and the synchronization control section controls a phase of the reference waveform signal according to the pulse correlation detection signal and the difference detection signal.