MELPe or MELP vocoder for secure portable device
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From: R. Chen on 21 Jan 2006 23:55 For secure portable device that is based on 533MHz Power PC processor or Pentium, we would like to use low rate vocoder. We realized that MELP or MELPe vocoder may be best for rates between 600 and 2400 bps. Do we need DSP or can we use simpler and cheaper solution such as the Power PC/Pentium processor itself? If we need to use DSP implementation, which DSP/implementation be the best? RC
From: Steve Underwood on 22 Jan 2006 00:09 R. Chen wrote: > For secure portable device that is based on 533MHz Power PC processor or > Pentium, we would like to use low rate vocoder. We realized that MELP > or MELPe vocoder may be best for rates between 600 and 2400 bps. Do we > need DSP or can we use simpler and cheaper solution such as the Power > PC/Pentium processor itself? > If we need to use DSP implementation, which DSP/implementation be the best? > RC A DSP to run MELP is <$2. Which Pentium is cheaper than that? Steve
From: NS on 22 Jan 2006 00:16 > For secure portable device that is based on 533MHz Power PC processor or > Pentium, we would like to use low rate vocoder. We realized that MELP > or MELPe vocoder may be best for rates between 600 and 2400 bps. That is probably correct, MELPe is an excellent choice for vocoder at rates 600-2400 bps. MELPe (Enhanced MELP [Mixed-Excitation Linear Predictive]) vocoder (known as military standard MIL-STD-3005 and NATO STANAG 4591) is probably an excellent choice vocoder at ranges of 2400 bps and below (2400, 1200, 600 bps). > Do we > need DSP or can we use simpler and cheaper solution such as the Power > PC/Pentium processor itself? I am assuming that the Power PC/Pentium processor is the main processor in your system, and that the DSP may be considered as co-processor. You can probably use the Power/PC or Pentium processor itself for full duplex MELPe vocoder, and that would require 20-30% CPU, depending on the implementation and the amount of optimization. You may try Compandent, who are the masters of MELPe and MELP implementations, and they can probably help you. See: http://www.melpe.com Very efficient multi-channel implementations are available for PC & Workstations running under Windows, Unix, Linux, MacOS etc.., in addition to a wide variety of multi-channel DSP implementation such as TMS320c54xx, TMS320c55xx, TMS320c64xx, OMAP etc.. Compandent's high-quality and 'certified' MELP / MELPe implementations were created by the same world-class speech coding & DSP experts of Compandent, who contributed to the official MELPe standard (along with other excellent experts & engineers from TI, SignalCom/MS, AT&T, & Thales) in project & process that was initiated, led, and sponsored by NSA & NATO. > If we need to use DSP implementation, which DSP/implementation be the best? This depends on your requirements, I would bet on the TMS320c55xx as a good choice for portable device. See for more information and FAQ: http://www.melpe.com http://www.Compandent.com/melpe_faq.htm http://www.Compandent.com/products_melpe.htm
From: NS on 22 Jan 2006 00:19 Steve Underwood wrote: > R. Chen wrote: > >> For secure portable device that is based on 533MHz Power PC processor >> or Pentium, we would like to use low rate vocoder. We realized that >> MELP or MELPe vocoder may be best for rates between 600 and 2400 bps. >> Do we need DSP or can we use simpler and cheaper solution such as the >> Power PC/Pentium processor itself? >> If we need to use DSP implementation, which DSP/implementation be the >> best? >> RC > > > A DSP to run MELP is <$2. Which Pentium is cheaper than that? > > Steve I guess he meant that the Power PC/Pentium processor is the main processor in his system, and that the DSP may be considered as an optional co-processor.
From: Vladimir Vassilevsky on 22 Jan 2006 12:15
Steve Underwood wrote: > R. Chen wrote: > >> For secure portable device that is based on 533MHz Power PC processor >> or Pentium, we would like to use low rate vocoder. We realized that >> MELP or MELPe vocoder may be best for rates between 600 and 2400 bps. >> Do we need DSP or can we use simpler and cheaper solution such as the >> Power PC/Pentium processor itself? >> If we need to use DSP implementation, which DSP/implementation be the >> best? >> RC > > > A DSP to run MELP is <$2. Which Pentium is cheaper than that? I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + 10k, MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. What is the DSP that is under $2 and can run MELP? I suggest something like Blackfin/TMS55xx, but those DSPs are about $8 in quantities. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com |