Patent ID: 8213545

Claim:
A radio receiving apparatus comprising: a first synchronization circuit that synchronizes an incoming signal with a first reference signal; a second synchronization circuit that synchronizes the incoming signal with a second reference signal based on the first reference signal when synchronization is established in the first synchronization circuit; and a demodulation section that demodulates the incoming signal based on one of synchronization information output from the first synchronization circuit and synchronization information output from the second synchronization circuit, wherein: the first synchronization circuit comprises a first correlation section that determines a correlation between the incoming signal and a first pulse template received as input at a timing corresponding to the first reference signal; the second synchronization circuit comprises a second correlation section that determines a correlation between the incoming signal and a second pulse template received as input at a timing corresponding to the second reference signal; and the first pulse template has a longer width than a width of the second pulse template, wherein the first synchronization circuit further comprises: a first pulse template generation section to generate the first pulse template, a first variable delay section to output a first delay signal to the first pulse template generation section to change an amount of delay of the first pulse template, and a first threshold decision section to output a control signal to one of the second synchronization circuit or the first variable delay section based on the determined correlation between the incoming signal and the first pulse template, and wherein the second synchronization circuit further comprises: a second pulse template generation section to generate the second pulse template, a second variable delay section to output a second delay signal to the second pulse template generation section to change an amount of delay of the second pulse template, and a second threshold decision section to output a control signal to one of the demodulation section or the second variable delay section based on the determined correlation between the incoming signal and the second pulse template.