Classic
Classic
SPR Robust TM 800 bps vocoder is based on Sinusoidal Pulsed Representation (SPR) model, providing high quality and other superior characteristics inherent to this model.
Moreover, the vocoder contains Forward Error Correction (FEC) scheme, which is integrated into vocoder on base of "source-channel coding" approach and provides high robustness of the vocoder to channel errors.
Features:
We used ITU-T P.50 multilanguage speech base and ITU-T P.862 utility to estimate speech quality.
In clear channel SPR Robust 800 bps vocoder provides speech quality near to SPR Classic 600 bps vocoder. However, robustness and all other characteristics of the vocoder excel considerably appropriate characteristics of the well-known vocoders.
SPEECH QUALITY
We passed encoded bit streams through AWGN channel simulator with various SNR and estimated quality of decoded speech.
SPR Robust 800 bps vocoder shows high robustness to channel errors with BER up to 5%.
ROBUSTNESS
Time delay is very important characteristic of communication system. Algorithmic delay of vocoder does play determinative role in total delay. Well known, the delay more than 100 ms is not acceptable for normal conversation.
SPR Robust 800 bps vocoder provides 100 ms delay. It is better, than MELPe 600 (110 ms).
Frame size is 80 ms (640 speech samples).
ALGORITHMIC DELAY
SPR Robust 800 bps is very effective vocoder and requires very little of the computing resources.
Less than 21 MIPS for TI's C55xx.
COMPUTING COMPLEXITY
SPR Robust 800 bps vocoder needs uniquely little memory, providing high rate of the quality/cost.
MEMORY USAGE
SPR Robust 800 bps vocoder is available right now for TI's C55xx DSP and for PC (Win32) platforms and also is available for any other DSP, RISC or general-purpose platform during two-three months.
AVAILABILITY
REQUEST
REQUEST
