From 41cf2b306a210c3600c1c35a8e952679a94c00a6 Mon Sep 17 00:00:00 2001
From: Tom Rondeau <trondeau@vt.edu>
Date: Mon, 29 Aug 2011 17:37:38 -0400
Subject: digital: created a separate DQPSK constellation that does not gray
code inside the block. This forces a slower decision making routine but
allows differential encoding. Gray coding is done using pre_diff_code.
---
gr-digital/lib/digital_constellation.cc | 80 +++++++++++++++++++++++++++++++++
1 file changed, 80 insertions(+)
(limited to 'gr-digital/lib/digital_constellation.cc')
diff --git a/gr-digital/lib/digital_constellation.cc b/gr-digital/lib/digital_constellation.cc
index 2263bba0bc..ed6d32bcb0 100644
--- a/gr-digital/lib/digital_constellation.cc
+++ b/gr-digital/lib/digital_constellation.cc
@@ -407,6 +407,20 @@ digital_constellation_qpsk::digital_constellation_qpsk ()
d_constellation[1] = gr_complex(SQRT_TWO, -SQRT_TWO);
d_constellation[2] = gr_complex(-SQRT_TWO, SQRT_TWO);
d_constellation[3] = gr_complex(SQRT_TWO, SQRT_TWO);
+
+ /*
+ d_constellation[0] = gr_complex(SQRT_TWO, SQRT_TWO);
+ d_constellation[1] = gr_complex(-SQRT_TWO, SQRT_TWO);
+ d_constellation[2] = gr_complex(SQRT_TWO, -SQRT_TWO);
+ d_constellation[3] = gr_complex(SQRT_TWO, -SQRT_TWO);
+ */
+
+ d_pre_diff_code.resize(4);
+ d_pre_diff_code[0] = 0x0;
+ d_pre_diff_code[1] = 0x2;
+ d_pre_diff_code[2] = 0x3;
+ d_pre_diff_code[3] = 0x1;
+
d_rotational_symmetry = 4;
d_dimensionality = 1;
calc_arity();
@@ -418,8 +432,74 @@ digital_constellation_qpsk::decision_maker(const gr_complex *sample)
// Real component determines small bit.
// Imag component determines big bit.
return 2*(imag(*sample)>0) + (real(*sample)>0);
+
+ /*
+ bool a = real(*sample) > 0;
+ bool b = imag(*sample) > 0;
+ if(a) {
+ if(b)
+ return 0x0;
+ else
+ return 0x1;
+ }
+ else {
+ if(b)
+ return 0x2;
+ else
+ return 0x3;
+ }
+ */
+}
+
+
+/********************************************************************/
+
+
+digital_constellation_dqpsk_sptr
+digital_make_constellation_dqpsk()
+{
+ return digital_constellation_dqpsk_sptr(new digital_constellation_dqpsk ());
}
+digital_constellation_dqpsk::digital_constellation_dqpsk ()
+{
+ d_constellation.resize(4);
+ d_constellation[0] = gr_complex(+SQRT_TWO, +SQRT_TWO);
+ d_constellation[1] = gr_complex(-SQRT_TWO, +SQRT_TWO);
+ d_constellation[2] = gr_complex(-SQRT_TWO, -SQRT_TWO);
+ d_constellation[3] = gr_complex(+SQRT_TWO, -SQRT_TWO);
+
+ d_pre_diff_code.resize(4);
+ d_pre_diff_code[0] = 0x0;
+ d_pre_diff_code[1] = 0x1;
+ d_pre_diff_code[2] = 0x3;
+ d_pre_diff_code[3] = 0x2;
+ d_apply_pre_diff_code = true;
+
+ d_rotational_symmetry = 4;
+ d_dimensionality = 1;
+ calc_arity();
+}
+
+#include <cstdio>
+unsigned int
+digital_constellation_dqpsk::decision_maker(const gr_complex *sample)
+{
+ bool a = real(*sample) > 0;
+ bool b = imag(*sample) > 0;
+ if(a) {
+ if(b)
+ return 0x0;
+ else
+ return 0x3;
+ }
+ else {
+ if(b)
+ return 0x1;
+ else
+ return 0x2;
+ }
+}
digital_constellation_8psk_sptr
digital_make_constellation_8psk()
--
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