This implementation of a G.165 Line Echo Canceller (LEC) is designed to reduce or even cancel electrical echoes in the transmission of speech signals. The tail length of the echo suppression can be adjusted to system requirements. The algorithm is required in DECT telephony systems and similar applications.

Features

* Software controlled Coefficient Adaptation
* Software controlled Leakage
* Software controlled Non-linear Processor (NLP)
* Software controlled Tone Disabler
* Double Talk Detector with Adaptation Control
* Programmable allowable Tail Length

Specifications

* ~ 10 MIPS per channel (32 msec tail)
* < 2K bytes program memory
* 76 + 32*T bytes data memory (T = tail in msec)

Platforms

The algorithm is available for Analog Devices Blackfin and Texas Instruments TMS320C54x/C55x. The API for all platforms is designed to be independent of signal source and sink. The code is fully re-entrant allowing multi-channel applications to be easily realized.
We have demo code available for standard evaluation platform, e.g. C55 DSK or Blackfin EZKit which we can provide to our (potential) customer on short notice. If required, we can port the existing code to other platforms - all you need to do is ask.

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