CML Microcircuits, SPIRIT DSP Team on Low Bit-Rate RALCWI Vocoder IC

CML Microcircuits, a leading innovator and provider of low-power semiconductors for Global Wireless and Wireline communication markets, announced the introduction of a new RALCWI (Robust Advanced Low Complexity Waveform Interpolation) vocoder IC. The product is the result of a co-operation between CML Microcircuits and SPIRIT DSP. The new CML IC is named as the CMX618, which CML will market to worldwide communication markets based upon SPIRIT’s proprietary Low Bit-Rate Vocoder technology. The co-operation combines CML’s 39-year history of developing mixed-signal semiconductors for professional and leisure communication applications, with SPIRIT’s extensive experience in embedded voice products.

The CMX618 is a flexible, half-duplex, highly integrated RALCWI vocoder IC suited to both wireless and wireline voice applications such as voice scramblers, alarm systems, military field applications and digital professional/leisure two-way radios (DMR/dPMR) to name but a few examples.

RALCWI technology uses proprietary signal decomposition and parameter encoding methods, ensuring high speech quality at high compression rates. The CMX618 offers near toll quality voice performance at very low bit rates, with independent MOS scores indicating that the CMX618 generates sound quality comparable with a standard codec running at bit rates above 4000bps.

The CMX618 includes an integrated voice audio codec, offering a complete analogue voice to low bit rate vocoded data function. There are 3 programmable vocoding rates: 2050bps, 2400bps or 2700bps and when combined with the embedded FEC, provides an overall bit rate of 3600bps. Frame length is selectable from 20, 40, or 60 ms without FEC, 60 or 80 ms can be selected with FEC protected frames. The selectable integral Viterbi decoder can use soft-decision metrics to improve its decoding ability. The FEC can also be used separately, so that data can be decoded/error-corrected, then re-encoded and forwarded on. This feature is particularly useful in voice repeaters, providing optimal voice performance and maximum range.

CML also offers designers the CMX608, a vocoder option without the integrated audio codec. This enables the use of an external audio codec solution. Both the CMX618 and CMX608 are free from any licence and royalty costs, fully meeting the requirements of high performance low bit rate digital voice applications. The CMX618 and CMX608 are available in small low power 48-pin VQFN and LQFP packages. An evaluation kit is available (EV6180), facilitating quick and easy evaluation. Connections are provided for audio input and output, power supply and a serial bus (C-BUS) header for connection to a host microcontroller.

About CML
CML Microcircuits (CML) is a member of the CML Microsystems Plc group (LSE:CML), specialising in the design, development and marketing of extremely low-power semiconductor products for Global Wireless and Wireline communications applications. Founded in 1968, the company is headquartered near London, UK with strategic locations in the USA, Singapore and China.

SPIRIT DSP employs 140 professionals, and has been in the international software licensing business since 1992. A bootstrap company, SPIRIT has been profitable for 15 years. For the last 10 years SPIRIT’s focus has been voice, audio, video and data communication software products. SPIRIT counts among its customers Adobe, Agere, Arima Communications, ARM, Atmel, Cisco, Compal, Flextronics, Ericsson, HP, HTC, Kyocera, LG, MediaRing, Microsoft, National Semiconductor, NEC, Nortel Networks, NXP, Oracle, Paltalk, Panasonic, Polycom, Quanta, Radvision, Samsung, Siemens, Texas Instruments, Toshiba and Trinity Convergence, among 200+ other communication OEMs and software vendors. SPIRIT communication software is used in over 80 countries and powers more than 100 million embedded voice channels. SPIRIT DSP is a member of major voice-related developer communities, including Analog Devices Collaborative, Intel(R) Developer Network, ARM(R) Connected Community, Philips Nexperia Partnership, TI Third Party Network, TI OMAP Developer Network for Wireless handsets and PDAs. SeeStorm is a SPIRIT affiliate for synthetic video conferencing.