From: drowe67 Date: Sat, 3 Feb 2018 19:43:52 +0000 (+0000) Subject: a little rewording X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=07f5853be3404beda7ec43c4e0d5781fc758fea9;p=freetel-svn-tracking.git a little rewording git-svn-id: https://svn.code.sf.net/p/freetel/code@3394 01035d8c-6547-0410-b346-abe4f91aad63 --- diff --git a/codec2-dev/README_fsk.txt b/codec2-dev/README_fsk.txt index 4638566f..fb95ad1d 100644 --- a/codec2-dev/README_fsk.txt +++ b/codec2-dev/README_fsk.txt @@ -51,23 +51,24 @@ Built as part of codec2-dev, see README for build instructions. $ ./fsk_get_test_bits - 5000 | ./fsk_mod 2 9600 1200 1200 1200 - - | ./fsk_demod -p 8 2 9600 1200 - - | ./fsk_put_test_bits - FSK BER 0.000000, bits tested 4900, bit errors 0 - In this example, the -l and --lbr options are left out setting the modem - up in "high speed" mode. In this mode, the demodulator operates on blocks of - 24 symbols at a time. In modes with a higher bitrate, this allows the modem - to operate with a much lower bit rate. High speed mode is well suited to - applications without much tolerance for latency or with limited processing - power and memory, such as PTT digital voice. + In this example, the -l and --lbr options are left out setting the + modem up in "high speed" mode. In this mode, the demodulator + operates on blocks of 24 symbols at a time. This allows the modem + to operate with a lower latency. High speed mode is well suited to + applications without much tolerance for latency or with limited + processing power and memory, such as PTT digital voice. - In this example, the -p (or --conv) option is used. This specifies the - downconverted symbol size. The symbol period (Ts) must be divisible by - the supplied P parameter. In this case, Fs is 9600 and Rs is 1200, so Ts - is Fs/Rs, which is 8. In this case, 8 is the maximum P value allowed, - though 4 and 2 would also work. If P is not divisible by Ts, a failed - assert will fire and fsk_demod will exit. If -p is not supplied, it - will default to match Ts. In general, lower values of P result in less - memory use and CPU time spend, but may result in worse modem preformance. - P should be left alone unless CPU and memory usage needs to be lowered - for the application. + In this example, the -p (or --conv) option is used. This specifies + the downconverted symbol size. The symbol period (Ts) must be + divisible by the supplied P parameter. In this case, Fs is 9600 + and Rs is 1200, so Ts is Fs/Rs, which is 8. In this case, 8 is the + maximum P value allowed, though 4 and 2 would also work. If P is + not divisible by Ts, a failed assert will fire and fsk_demod will + exit. If -p is not supplied, it will default to match Ts. In + general, lower values of P result in less memory use and CPU, but + may result in worse modem preformance. P should be left alone + unless CPU and memory usage needs to be lowered for the + application. (TODO, make this easier to understand, perhaps with figure)