The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 2004
Filed:
Apr. 28, 2000
Kiyoshi Nomura, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A null symbol position detecting method, apparatus, and receiver for quickly and accurately detecting a null symbol from a broadcast signal containing it in any broadcast signal receiving environment. A digital audio broadcast (DAB) signal is received and tuned in and this signal is I/Q-demodulated. The I and Q signal obtained by the I/Q demodulation are delayed by an I-component delay circuit and a Q-component delay circuit respectively by one valid symbol period to form a delay signal Id and a delay signal Qd respectively. Correlation is obtained between the delay signals Id and Qd and the signals I and Q which are not delayed. The peak of this correlation is determined by a peak decision circuit. The level pattern of the peak is detected by a level pattern decision circuit. If a low-level peak is found, the length of the null symbol period is computed by a time interval decision circuit to determine whether the length is the same as that of the null symbol included in the received and tuned-in DAB signal, thereby detecting the null symbol position.