Cell-phone headsets often face two problems: poor performance in noisy environments and inconvenient pairing processes that enable the headset and phone to talk to each other. Yet the BC6130, BC6140, and BC6150 BlueCore ROM Bluetooth chips from CSR not only solve these challenges, they also produce a new level of performance in cell-phone handsets. They feature a faster user interface, Handsfree Profile (HFP) multipoint, and programmable audio prompts.

The BlueCore ROM chips fully comply with Bluetooth v2.1 + EDR (Enhanced Data Rate) for mono applications. They also support CSR’s Proximity Pairing Technology, which lets the headset find the closest Bluetooth source device and pair with it. The headset initiates the pairing activity, and the user simply accepts the incoming pairing invitation on the source device. A highly optimized application significantly accelerates the user experience when connecting calls.

The BC6140 and BC6150 include CSR’s fifth-generation Clear Voice Capture (CVC) speech processing system. This 24-bit, 64 MIPS DSP implements the voice algorithms. The CVC 5.0 modular suite of advanced speech processing algorithms works with both single and dual-microphone headsets. It brings a range of powerful audio enhancement technologies to the near-end user and provides excellent speech quality for the far end.

The dual-microphone option delivers more than 30-dB dynamic noise suppression in harsh acoustic conditions regardless of the direction of noise. Also, CVC 5.0’s packet loss and bit error concealment technologies improve the robustness of incoming wireless audio and mask any breakup in the signal caused by surrounding RF interference. Such breakup can come from being close to a “noisy” device such as a microwave oven or simply from cross-body interference.

At the near end, the suite of audio enhancements provides a unique noise suppression algorithm to significantly reduce unwanted noise embedded in the received speech. The software’s adaptive equalizer improves intelligibility by shaping the received speech to exploit the naturally sensitive areas of the human hearing system. The system also fully compensates for the background noise the user is experiencing by adapting to external noise levels.

An automatic gain control dynamically adjusts the amplitude of the received speech to ensure that the headset user can hear the incoming voice clearly. An acoustic echo canceller reduces acoustic coupling between the loudspeaker and the microphone. Single-channel and dual-channel noise suppression algorithms dynamically process the microphone signals to deliver clear speech at the far end of the link. Equalization and gain control further strengthen and amplify speech.

Dual-microphone dynamic noise reduction with CVC 5.0 on the BC6150 provides the very highest levels of delivered speech clarity to the far end, despite any presence of significant dynamic background noise from any direction. This architecture allows CVC 5.0 to separate the voice signals of interest from the noise using proprietary signal extraction techniques. The rich suite of DSP algorithms in CVC 5.0 allows users to hear and be heard much more clearly, extending the usability of Bluetooth headsets into more acoustically challenging environments.

The CVC Parameter Manager tool permits manufacturers to tune software blocks at product design to achieve optimum performance with any type of headset. With CSR’s power-efficient DSP-based algorithms, headset suppliers can also achieve longer battery life as well as superb noise reduction.

Receive sensitivity is –90 dBm. The transmit power is 7.5 dBm on the BC6130 and BC6140 and 8 dBm on the BC6150. All three chips feature low power consumption with current draws in the 6.5- to 17-mA range depending on model and operating mode. The BC6130 and BC6140 come in a 7- by 7-mm quad flat no-lead (QFN) package, and the BC6150 comes in an 8- by 8-mm QFN. The chips are sampling now.