EDGE: Add 8-PSK modulator and demodulator
Setup correlator and detection process similar to the GMSK
receiver chain. Require 4 SPS sampling on both Rx and Tx paths
as 1 SPS sampling adds too much distoration for 8-PSK recovery.
Core receiver operations still run at 1 SPS with the exception
of fractional delay filtering, which runs at the higher rate.
Perform linear equalization to handle the Gaussian pulse
induced ISI. The fixed impulse response used for equalizer tap
calculation consists of combined EDGE pulse shape filter and
effects of the downsampling filter. Note that the non-adaptive
equalizer corrects for modulation induced band limiting and
does not account for or compensate for fading channel effects.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
diff --git a/Transceiver52M/Resampler.h b/Transceiver52M/Resampler.h
index cf2defd..072ec92 100644
--- a/Transceiver52M/Resampler.h
+++ b/Transceiver52M/Resampler.h
@@ -59,6 +59,11 @@
*/
size_t len();
+ /*
+ * Enable/disable history
+ */
+ void enableHistory(bool on);
+
private:
size_t p;
size_t q;
@@ -68,6 +73,7 @@
float **partitions;
float *history;
+ bool history_on;
bool initFilters(float bw);
void releaseFilters();