Commit Graph

18 Commits

Author SHA1 Message Date
Andreas Eversberg fd3b4dae50 FSK modulator improvements
1. Phase is now changed proportional to the time of the bit change, if
   it happens somewhere between samples. The amount of phase change per
   bit is now the same for all bits, no matter how many samples
   currently lay inside this bit.

2. IIR filter is removed, because it causes distortions. A cosine shape
   is now used to transit between phase change of F0 to F1 and vice
   versa. This limits the spectrum. This filter is optional.
2022-12-16 12:43:19 +01:00
Andreas Eversberg 2b7efedc48 Refactoring jitter buffer
Features are:
 * Packet based buffer
 * Random in, first out
 * Adaptive delay compensation (voice)
 * Fixed delay (data, optionally MODEM/FAX)
 * Interpolation of missing frames
 * Any sample size
2022-10-23 16:56:27 +02:00
Andreas Eversberg c2f14834e5 Rename dbm0 (level) to speech (level)
In mobile communications we use speech level instead of milliwatts.
The deviation (FM) is always based on speech level, not on 1 milliwatt.
2019-12-08 17:24:36 +01:00
Andreas Eversberg 445af0c0a2 Add filter switch to FSK modulator 2019-11-29 15:58:32 +01:00
Andreas Eversberg 6dcc8baad4 Split FSK modem code into separate modulator and demodulator 2019-11-29 15:58:32 +01:00
Andreas Eversberg e9a7f610ee Compandor: Remove unused option for unaffected level 2018-10-14 13:07:25 +02:00
Andreas Eversberg 6277753574 Minor debug message corrections 2018-02-15 08:00:18 +01:00
Andreas Eversberg 0b129d3c7f libdisplay: Removing dependency from libmobile 2018-02-15 08:00:14 +01:00
Andreas Eversberg 1a341f6b4e Restructure: Move debug from common code to 'libdebug' 2017-12-03 08:45:58 +01:00
Andreas Eversberg ed31a26eba Restructure: Move sample from common code to 'libsample' 2017-12-03 08:45:48 +01:00
Andreas Eversberg b605da1aff Restructure: Move timer from common code to 'libtimer' 2017-11-13 20:00:52 +01:00
Andreas Eversberg ee3fbeb03b Split call control from built-in call console by using MNCC layer 2017-11-05 16:58:31 +01:00
Andreas Eversberg b32e0ab602 Implementation of RX level squelch (for A-Netz and B-Netz)
Use -S <dB> for setting RF level or use -S auto for auto level.

When squelch closes, audio is muted. If squelch is closed for some
seconds (depending on network), call is released. (RF loss condition)

The previous loss detection has been removed
2017-10-22 19:23:08 +02:00
Andreas Eversberg ba036de226 Add function to display measurements on screen
Use 'm' key to toggle display.
2017-10-12 19:46:30 +02:00
Andreas Eversberg 743d147d16 SDR: Turn TX power off if requested by network
The power level is ramped smoothly within 1 ms up or down.

R2000, AMPS and C-Netz turn off power when voice channel is not i use.

C-Netz turns off power between OgK timeslots.
2017-09-01 18:42:46 +02:00
Andreas Eversberg 1c2e9180a2 Radiocom 2000: Use high-pass filter to remove supervisory signal 2017-09-01 18:42:45 +02:00
Andreas Eversberg 534411d660 New common FSK implementation, replaces all individual implementations 2017-08-09 17:27:13 +02:00
Andreas Eversberg ffd3b848e1 Implementation of "Radiocom 2000", the analog French mobile network 2017-08-09 17:27:12 +02:00