• Digital Terrestrial Broadcasting
• JITTER MEASUREMENTS "DVD-RAM Jitter Analyzing Technique"

2. Digital Radio

(1) What is Digital Radio?

A digital radio is a new sound broadcasting service called ISDB-TSB (Integrated Service Digital Broadcasting-Terrestrial for Sound Broadcasting).

As of August 2006, the test broadcasting is aired from Tokyo Tower for Kanto area; Mt. Ikoma for Kansai area in a frequency of 190.214286 MHz (channel 7 in VHF).

In addition to a high-quality sound like a music CD, a digital radio can offer various service (e.g., still picture, character, simple motion picture) in the broadcasting system.

Such mobile stations as car radio and pocket receiver can also expect a clear reception as well as the fixed stations. (A dedicated terminal is required for reception.)

In the test broadcasting in both Kanto and Kansai areas, the transmission capacity is divided into eight segments.

The band of 1 segment is about 300 kbps, and 3 segment broadcasting may be performed in the future.

Six channels consisting of five 1 segment and one 3 segment are used for test broadcasting in Kanto area; eight channels consisting of eight 1 segment is used in Kansai area.

As for the digital terrestrial radio broadcasting, OFDM (Orthogonal Frequency Division Multiplex) is used for a multiplex system as well as digital terrestrial TV to avoid multipass obstruction.

The OFDM is used to transmit the information that divided and modulated with orthogonal multiple carriers.

Since the modulation method and error correction code of each segment can be changed, up to three hierarchical layers can be transmitted.

The MPEG-2 AAC SBR (Advanced Audio Coding-Spectral Band Replication) is mostly used for the audio compression.

The simple motion picture compressed with MPEG-4 H.264/AVC (Advanced Video Coding) can also be transmitted as well as the 1 segment broadcasting of the digital terrestrial TV.

The 5.1 ch surround broadcasting not used for the 1 segment broadcasting is also scheduled to be offered in 3 segment broadcasting.

Comparing reception system of digital radio and TV

(2) Transmission Parameter in 1 Segment Format

The 1 segment operation is mostly performed in Mode 3.

Transmission parameter in 1 segment format [Zoomed]

(3) Transmission Parameter in 3 Segment Format

The 3 segment radio is mostly performed in Mode 3, however, Mode 2 is used in some cases.

Transmission parameter in 3 segment format [Zoomed]