FM (frequency modulated) signal for SDR is generated by varying the
phase, where phase variation is proportional to input signal. It is
seen that, the larger phase increments leads to discontinuities in
the signal recovered after demodulation. Reducing the extent of phase
variation with respect to input signal, equivalent to reducing the
modulation index.
Tested using FM receiver flow graph in gnuradio-companion.
Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: Prashant Laddha <prladdha@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The common implementation for sin/cos in include/linux/fixp-arith.h
has been improved recently to provide higher precision.
Replacing native implementation of sin/cos in vivid sdr with common
implementation. This serves two purposes:
1. Improved accuracy: the native implementation based on the Taylor
series is more prone to rounding errors.
2. Reuse of common function: this is better compared to maintaining
native versions for each driver.
Suggested by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: Prashant Laddha <prladdha@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This adds support for an SDR capture device. It generates simple
sine/cosine waves. The code for that has been contributed by
Antti.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
