Hi James, Well done on finding your problem and getting your SM1000 to work. Quite a few people have reported that the SM1000 works better with an external headset-style microphone. I am not sure why - it would be an interesting project to find out why.
Yes it's true the FreeDV GUI program has Speex noise reduction software, but the SM1000 does not. 22dB is a fine SNR - that's about as good as it gets. Well done. Thank you for working on 700B port. I would be happy to work with you on this project. Yes you have the first two steps correct. When you write the programs (1) and (2) below please email me off-list and I will arrange SVN write access so you can check the code in. Thanks, David On 18/01/16 19:19, DB.JIANG wrote: > > Dear David, > Thanks for your advice! > I had found out the TX audio distortion of my SM1000 is causing by the > MIC amp., which I used is a noise one. And I also found the SM1000 may > be more sensitive to the background noise than FreeDv, > because FreeDv had involve the prefilter to handle the MIC signal.Am I > right? The SNR reach 22db from SM1000 to FreeDv and sync is steady. I > will test it on air and report later. > Refer to 700B mode, I had read your post on Sep. 24,2015. It seems not > an easy job for me. But for the amazing performance on noise band, I > will try anyway. The step you advised are as below: > 1. First step is to write a unit test to printf out the memory > usage of the cohpsk modem states. > 2. Next step is a unittest that runs on a STM32F4 Discovery board to > profile the CPU load. > Right? > Thanks and Best Regards, > James Jiang > > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > > > > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
