China digital radio (CDR)

Convergent/China Digital Radio (CDR)

Frequencies	106.1 MHz
Frequency Range	106.1 MHz - 106.1 MHz
Mode	USB
Modulation	OFDM
ACF	—
Emission Designator	—
Bandwidth	100 kHz,200 kHz,300 kHz,400 kHz,500 kHz
Location	China
Short Description	Convergent Digital Radio (CDR) or China Digital Radio is an in-band-on-channel (IBOC) digital radio broadcasting format used in China. It can be found in multiple bandwidth configurations with different modulation formats.
I/Q Raw Recording	Download file
Audio Sample

Convergent Digital Radio (CDR), also known as China Digital Radio (CDR), is an In-Band On-Channel (IBOCIn-Band On-Channel (IBOC) is a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency.) digital radio broadcasting standard that operates in the FMFrequency Modulation band (88 MHzMegaHertz (MHz) 10^6 Hz to 108 MHzMegaHertz (MHz) 10^6 Hz). It is also known as ITU Digital System H.

Frequencies

FMFrequency Modulation Broadcast Band (88 MHzMegaHertz (MHz) 10^6 Hz to 108 MHzMegaHertz (MHz) 10^6 Hz)

Characteristics

CDR is a flexible system that may be configured to suit different bandwidth requirements. ITU-R recommendation BS.1114-12 allows for 6 configurations which allows for digital only operation (Modes A, B) or may flank analog signals in an IBOCIn-Band On-Channel (IBOC) is a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency. configuration (Modes C-F). CDR is a OFDMOrthogonal Frequency-Division Multiplexing system that allows for simultaneous delivery of multiple audio and data streams. CDR uses frequency-time interleaving and LDPC forward error correction to improve performance against multipath and interference. Furthermore, the system may be configured with different OFDMOrthogonal Frequency-Division Multiplexing transmission modes, modulations including QPSKQuadrature Phase-Shift Keying (2 bits per symbol), 16-QAMQuadrature Amplitude Modulation or 64-QAMQuadrature Amplitude Modulation, and LDPC rates to allow for various net bitrates. This system uses, but is not limited to, the DRA+ audio codec.

Decoding Software

No open source software as of now.

Additional Links

• Chinese Wikipedia for CDR
• ITU-R BS.1114-12: Systems for terrestrial digital sound broadcasting to vehicular, portable and fixed receivers in the frequency range 30-3000 MHz
• Document comparing digital radio standards

Additional Images

Full image of type C CDR Another image of CDR Close up image of upper digital signal of type C CDR system. Sidebands around 91.4 MHzMegaHertz (MHz) 10^6 Hz, in Guangzhou, Southern China