CSR creates industry's first audio processor with Bluetooth for handsets

CAMBRIDGE, UK: CSR has announced the CSR7810, a unique product that embeds an audio processing platform and a handset Bluetooth radio onto a single chip.

Users often struggle to make themselves heard on a mobile phone - background noise from traffic, roadworks or even a noisy railway station can render conversations inaudible. CSR7810 contains voice processing technology for handsets designed to radically improve the audio quality of conversations in extremely noisy environments.

"Quality of audio has a significant impact on consumer experience with handsets," said Matthew Phillips, Senior Vice President for CSR's Handset Business Unit. "Our inventive audio platform architecture is providing our customers with a cost effective and space efficient way to provide crystal clear voice processing along with Bluetooth radio connectivity to mobile phone platforms."

By combining Bluetooth and voice processing functionality in a single chip, CSR7810 significantly reduces manufacturing costs and design integration time as well as overall PCB space. Existing handset designs that incorporate a CSR Bluetooth device can be easily upgraded to CSR7810 and benefit from noise cancellation.

"The mobile handset has evolved tremendously over the past decade," said Raj Gawera, Vice President of Marketing for CSR's Handset Business Unit. "However one area that hasn't changed much is the user audio experience – until now. Cellular operators are upgrading their networks to have wider audio pipes to improve the audio experience. On the mobile handset side, there is the increased use of speech recognition technology. Operating systems such as Google Android 2.0 contain built-in speech recognition to enter text and control phone functions. All of this means that active noise cancellation will quickly become a mandatory technology on high end phones."

CSR7810's noise cancellation uses signals from one or two microphones (digital or analogue) to remove background noise from the transmitted voice signal. By 'listening' to both the caller's voice and the surrounding environment, and then calculating the difference between the two signals, CSR's dual-microphone noise cancellation makes a big difference to audibility.

CSR's Audibility Enhancement algorithms improve the incoming audio quality by dynamically adjusting the volume and equalisation at the earpiece to compensate for background noise. The Voice Equalisation and Echo Cancellation for Speakerphone mode from CSR's Clear Voice Capture (CVC) hands-free configuration technology is also included. This mode uses a single microphone noise reduction and echo cancellation algorithm to improve the transmitted and received audio quality, which allows handsets to support a speakerphone whilst still maintaining high voice quality.

The Kalimba DSP, a very power-efficient architecture optimised for low power connectivity applications, is at the heart of CSR7810. Kalimba is the lynchpin of CSR's audio platform solutions. As audio functionality becomes an increasingly prominent capability in more products utilising connectivity, CSR is receiving customer requests to incorporate Kalimba into ever more devices. CSR's Kalimba DSP has shipped in over 100 million Bluetooth devices and this expertise and success provides a proven solution for many other categories of products.