Patent ID: 7715886
Filing Date: 2010-05-11
Classification: H04B,H04W,Y02D

Abstract:
1. A reception apparatus for receiving a broadcast wave carrying a signal string transmitted on a time-division multiplexing basis, the signal string including a modulation signal generated by digital modulating a desired signal and another signal using a predetermined modulation method, the reception apparatus comprising: a receiving unit operable to operate to receive the broadcast wave only during a time period for which part of the modulation signal corresponding to the desired signal is transmitted, and generate an analog input signal; an input stream generating unit operable to generate an input stream by analog-to-digital converting the input signal generated by the receiving unit; a storing unit operable to store the input stream in association with a generating time at which the receiving unit generates the input signal; and a demodulating unit operable to demodulate the input stream stored in the storing unit, by using a demodulation method corresponding to the predetermined modulation method, to obtain the desired signal, wherein the demodulating unit includes: a PLL (Phase Locked Loop) unit operable to generate a carrier and a clock based on the input stream; a digital demodulation unit operable to perform demodulation by using the carrier and clock generated by the PLL unit, to obtain the desired signal; and a demodulation control unit operable to control the storing unit and PLL unit so as to go through first, second, and third steps, in the first step, the storing unit outputs the input stream to the PLL unit, forward in an order of the generating time, beginning with a start of the input stream, so that the PLL unit performs an operation to establish synchronization based on the input stream output from the storing unit, in the second step which starts at or after a time when the PLL unit establishes the synchronization, the storing unit outputs the input stream backward in the order of the generating time, up to the start, so that the PLL unit tracks the input stream while maintaining the synchronization, and in the third step, the storing unit outputs the input stream forward in the order of the generating time, beginning with the start, so that the PLL unit generates the carrier and clock while maintaining the synchronization, and the digital demodulation unit performs the demodulation based on the carrier and clock, to obtain the desired signal.