Andreas Eversberg
0c9de251be
NMT: Implement Hagelbarger Code
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This will correct burst errors of received messages. If the message
is too corrupted, it will be ignored, because some element may not
match then. The digits and line signals are checked for consistency,
since they are repeated serveral times in a message.
2017-08-08 12:52:29 +02:00
Andreas Eversberg
085ceb9173
Minor fixes to compandor
2017-07-15 07:38:12 +02:00
Andreas Eversberg
ca10048e5c
Rename filter -> iir_filter (file name and instance name)
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This is useful when using fir_filter in the future.
2017-05-15 21:46:32 +02:00
Andreas Eversberg
438ce08add
SoapySDR support
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There is no time stamp handling. It is just TX'ing in advance and
synchronous to received RX rate.
2017-02-18 21:02:55 +01:00
Andreas Eversberg
58ebc15292
Add test to measure performance of FM modulation and filtering
2017-02-18 21:02:53 +01:00
Andreas Eversberg
7e45f556ce
Correcting all levels and move all remaining integer samples to sample_t
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The leves are based on the standards of each mobile network. They
are adjusted to the specified frequency deviation now.
2017-02-18 21:01:13 +01:00
Andreas Eversberg
bd7ccc5fa0
Add global DC-Filter and remove all individual DC-Filters
2017-02-18 21:01:12 +01:00
Andreas Eversberg
71e556e7ff
Work on emphasis filter: Neutral @ 1000 Hz; Use filter before de-emphasis
2017-02-18 21:01:11 +01:00
Andreas Eversberg
b3fd53b165
Test filter uses a dB graph to show the response graphically
2017-02-18 21:01:10 +01:00
Andreas Eversberg
7ea3bc188d
Move samples of int16_t format to sample_t, that is of type double
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This prepares the correction of all levels
2017-02-18 21:01:08 +01:00
Andreas Eversberg
ac0da3f76e
Filter improvement: LP and HP filters, added test function
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The -3 dB level at cut-off frequency is now maintained for multiple
iterations.
2017-02-18 21:01:04 +01:00
Andreas Eversberg
57993e3e48
Support for UHD SDR interface
2017-02-18 21:00:49 +01:00
Andreas Eversberg
d447be5e26
NMT: Rework on FSK process, no more requirement for special sample rates
2017-01-07 06:28:20 +01:00
Andreas Eversberg
1ea95de120
C-Netz: Use emphasis with 200 uS time constant
2016-10-23 08:46:05 +02:00
Andreas Eversberg
038ce9d1b7
Add info key 'i' to show some states.
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Currently showing C-Netz attached subscribers
2016-08-03 12:03:49 +02:00
Andreas Eversberg
c273bbc5ff
Remove console line before printing debugging and on exit
2016-07-24 12:31:08 +02:00
Andreas Eversberg
b3b42e8bc4
Cleanup warnings at autoconfig files
2016-07-24 12:31:06 +02:00
Andreas Eversberg
a6bd841247
NMT: Various fixes for SMS support
2016-07-24 12:31:05 +02:00
Andreas Eversberg
e7fa08b6df
NMT / SMS: Short Message Service support
2016-07-09 15:16:16 +02:00
Andreas Eversberg
64c829909b
NMT / DMS: User data facility support (required for SMS)
2016-07-09 11:27:24 +02:00
Andreas Eversberg
2ee51022f4
Rename 'compander' to 'compandor'
2016-06-20 19:37:56 +02:00
Andreas Eversberg
42eefe90bf
common code: Fixed de-emphasis by adding high pass filter
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This high-pass filter filters out DC and frequencies below 300 Hz.
Now de-emphases will not cause low frequencies to saturate audio level
range or cause too high levels on low frequencies.
2016-05-13 09:37:02 +02:00
Andreas Eversberg
0c99848120
common code: Make preemphasis 0 dB @ 1000 Hz
2016-05-01 15:14:57 +02:00
Andreas Eversberg
4356c93afa
common: Add pre and de emphasis, if the radio does not support it
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Connect to the oscillator of the transmitter - good girl!
You need to enable pre emphasis in this case.
Connect to the discriminator of the receiver - good boy!
You need to enable de emphasis in this case.
2016-04-24 15:14:56 +02:00
Andreas Eversberg
2a092b8cf7
Fixing compander
2016-04-24 15:10:25 +02:00
