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Technology
Sony's Proprietary WiDIF-HP Codec
In the wireless system, audio signals have to be transmitted within a limited wireless bandwidth. Transmitting
the highest possible quality audio in this limited bandwidth is the major issue for wireless microphone
development. In addition, low-latency audio transmission is another requirement of microphone applications.
To transmit the best quality audio within limited bandwidth, Sony developed a digital wireless transmission
system that employs a proprietary WiDIF-HP codec, which realizes both outstanding sound quality and low
latency.
The WiDIF-HP codec is characterized by the following key features.
Outstanding sound quality with 24-bit/48-kHz sampling
Low latency
Secure transmission
The Sony digital audio codec achieves an optimum balance between sound quality, bit rate, and latency,
while having the redundant bit assignment necessary for wireless transmission.
Channel Coding and Decoding
In order to ensure high quality audio signal transmission within the given bit rate limits, WiDIF-HP employs
synchronization technology to keep the error count as low as possible, along with error processing technology
that minimizes the risk of noise when an error occurs. These techniques were developed and optimized using
extensive simulation and field testing programs covering all wireless system operation aspects such as RF
signal attenuation, Doppler effect, RF reflections, and more. Signal encryption is also handled at the coding
stage.
8
WiDIF-HP Technology
Transmitter
24 bit
@48-kHz fs
AF
A/D
1152 kb/s
Receiver
De-modulated
Digital
Data
RF
De-modulator
Transmitter
24 bit
@48-kHz fs
AF
A/D
1152 kb/s
Receiver
De-modulated
Digital
Data
RF
De-modulator
CODEC
Audio Data
Down Sampling
&
192 kb/s
Bit Compression
Decripted
Audio Data
Channel Decoding
CODEC
Down Sampling
Audio Data
Channel Coding
&
192 kb/s
Bit Compression
Decripted
Audio Data
Channel Decoding
Encrypted
&
Channel Coding
Modulator
Packetized
Data
24 bit
CODEC
@48-kHz fs
Up Sampling
&
1152 kb/s
Bit Expansion
Encrypted
Digital
&
Modulator
Packetized
Data
24 bit
CODEC
@48-kHz fs
Up Sampling
&
1152 kb/s
Bit Expansion
Digital
RF
D/A
AF
RF
D/A
AF
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