Classic
Classic
SPR Robust TM 1000 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 1000 bps vocoder provides speech quality near to SPR Classic 800 bps vocoder, conseding to SPR Classic 1000 bps.
However, the vocoder keeps the speech quality in noisy channel, providing high robustness to errors.
SPEECH QUALITY
We passed encoded bit streams through AWGN channel simulator with various SNR and estimated quality of decoded speech.
SPR Robust 1000 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 1000 bps vocoder provides 100 ms delay. It is better in comparison with well-known vocoders for the same bit rate.
Frame size is 80 ms (640 speech samples).
ALGORITHMIC DELAY
SPR Robust 1000 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 1000 bps vocoder needs uniquely little memory, providing high rate of the quality/cost.
MEMORY USAGE
SPR Robust 1000 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
