DSP software makes HF radiocomms clearer

Edited by the Electronicstalk editorial team Nov 21, 2003

A novel complete Voice+Data over HF DSP software solution provides core functionality for voice/data-over-HF communication products.

A novel complete Voice+Data over HF DSP software solution provides core functionality for voice/data-over-HF communication products.

System designers can leverage a proven solution, which allows to focus their efforts on rapid product development, thus making the product more cost-effective and reducing time to market.

The solution can be effectively used for such applications as HF radios, HF modems, and voice- and datacommunications equipment for paramilitary applications such as police, emergency, fire and forestry services.

The solution combines a low-delay HF soft modem with Spirit's proprietary low bitrate LPC-MMBE vocoders, special FEC (forward-error-correction) and noise cancellation technology to make possible reliable and secure voice communication over high-frequency radio links even in noisy environment.

The underlying modem provides reliable, fast and cost-effective datacommunications over high-frequency radio links at rates from 75 to 4800bit/s, using standard single-tone waveforms compliant with MIL-STD-188-110A.

Unique forward error correction technique developed especially for Spirit's proprietary vocoders enhances voice quality under disturbing, noisy propagation conditions.

It can be effectively used for radio communications, confidential data transmission, wireless communications to ensure quality connection even on badly distorted channels.

The error protection procedure used in the algorithm allows stronger protection for most sensitive bits of the most sensitive parameters.

The autobaud feature of the modem allows it to automatically distinguish voice/data transmission and define the actual datarate adaptively.

An additional low-bitrate channel can be effectively used for data transmission, such as data monitoring and awareness data in the voice mode.

Powerful equalisation techniques combined with smart tracking systems provide reliable operation on HF channels with high fade rates and large multipath delay spread.

The solution has optional user-defined encryption feature for secure multipoint services.

Depending on configuration, the solution consumes up to 82MIPS, up to 46Kword of program memory and 42Kword of data memory (in half-duplex mode).

Evaluation versions of Spirit's Voice+Data over HF processor are available for PC, TMS320VC5416 and TMS320VC54CST platforms.