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authorBen Reynwar2013-01-18 09:25:23 -0700
committerBen Reynwar2013-01-18 09:25:23 -0700
commit6d094c4992ee0abc2788d8594572f26609d17c35 (patch)
treedf0495a15eed877f4e801cd2f9070df3499e9267 /gr-digital
parent2190f94d08855676a1f837c4520831d3987d1148 (diff)
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digital: Updated constellation_receiver_cv documentation.
Diffstat (limited to 'gr-digital')
-rw-r--r--gr-digital/include/digital_constellation_receiver_cb.h28
1 files changed, 4 insertions, 24 deletions
diff --git a/gr-digital/include/digital_constellation_receiver_cb.h b/gr-digital/include/digital_constellation_receiver_cb.h
index 3a14bb5de..92c31311f 100644
--- a/gr-digital/include/digital_constellation_receiver_cb.h
+++ b/gr-digital/include/digital_constellation_receiver_cb.h
@@ -41,36 +41,18 @@ digital_make_constellation_receiver_cb (digital_constellation_sptr constellation
float loop_bw, float fmin, float fmax);
/*!
- * \brief This block takes care of receiving generic modulated signals
- * through phase, frequency, and symbol synchronization.
+ * \brief This block does fine-phase and frequency locking and decision making.
* \ingroup sync_blk
* \ingroup demod_blk
* \ingroup digital
*
- * This block takes care of receiving generic modulated signals
- * through phase, frequency, and symbol synchronization. It performs
- * carrier frequency and phase locking as well as symbol timing
- * recovery.
- *
* The phase and frequency synchronization are based on a Costas loop
* that finds the error of the incoming signal point compared to its
* nearest constellation point. The frequency and phase of the NCO are
* updated according to this error.
*
- * The symbol synchronization is done using a modified Mueller and
- * Muller circuit from the paper:
- *
- * "G. R. Danesfahani, T.G. Jeans, "Optimisation of modified Mueller
- * and Muller algorithm," Electronics Letters, Vol. 31, no. 13, 22
- * June 1995, pp. 1032 - 1033."
- *
- * This circuit interpolates the downconverted sample (using the NCO
- * developed by the Costas loop) every mu samples, then it finds the
- * sampling error based on this and the past symbols and the decision
- * made on the samples. Like the phase error detector, there are
- * optimized decision algorithms for BPSK and QPKS, but 8PSK uses
- * another brute force computation against all possible symbols. The
- * modifications to the M&M used here reduce self-noise.
+ * The decicision making itself is performed by the appropriate method of the
+ * passed constellation object.
*
*/
@@ -87,13 +69,11 @@ protected:
/*!
* \brief Constructor to synchronize incoming M-PSK symbols
*
- * \param constellation constellation of points for generic modulation
+ * \param constellation constellation object for generic demodulation
* \param loop_bw Loop bandwidth of the Costas Loop (~ 2pi/100)
* \param fmin minimum normalized frequency value the loop can achieve
* \param fmax maximum normalized frequency value the loop can achieve
*
- * The constructor also chooses which phase detector and decision maker to use in the
- * work loop based on the value of M.
*/
digital_constellation_receiver_cb (digital_constellation_sptr constellation,
float loop_bw, float fmin, float fmax);