Detection method for the transmitter identification information signal in the null symbol of a DAB stream

US6134267A · kind A · utility

Assignee

• Sony International (Europe) GmbH · DE

Inventors

• Wolfgang Schafer · Düren, DE
• Jurgen Grassle · Tübingen, DE
• Markus Zumkeller · Schwaikheim, DE

Key dates

• Filing date: Sep 8, 1998
• Grant date: Oct 17, 2000
• Expiry date: Sep 8, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04H2201/20
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A DAB stream starts with a so-called null symbol for the receiver synchronization carrying a transmitter identification information, i.e. TII, signal. Each transmitter in the single frequency network is assigned a main id and a sub id for unique identification. This identification is mapped to a certain pattern with 16/8/4/2 set carrier pairs in the spectrum of the null symbol according to the DAB modes I-IV. Based on mode II which has 384 valid carriers a so called comb block is defined. For modes I and IV this block is repeated 4 and 2 times, respectively. For mode III only a half block is available. This pattern is transmitted every 2nd DAB frame in the null symbol. To detect the set carriers the steps of differential demodulation of TII pairs included in the spectrum (S.sub.1 (.omega.)) of every second null symbol of the incoming DAB stream (S1, S2, S3) to respectively obtain a demodulated null symbol, correction of carrier phases of the demodulated null symbol spectrum (S4), determination of a threshold (S7), and decision if a carrier is set or not by comparing the carrier level to the determined threshold (S6) are performed.