Timing recovery is a critical aspect of Digital Communications Receivers. This model uses a fractional sample delay implemented with a Farrow filter to create a symbol rate timing recovery subsystem. This is combined with a decision aided Carrier Recovery PLL. For testing, a transmitter with continuosly variable carrier frequency error and symbol rate error is included. Two versions of the transmitter are provided. One version uses Simulink's variable step solver to create a continuous time signal for re-sampling by the receiver. The other version uses the same fractional sample delay as in the receiver to implement the transmitter entirely in discrete time.
The updated version of these files supports QAM modulation of order 2 to 256 inclusive. It therefore supports PSK (2 QAM) and QPSK (4 QAM) as well.
References are cited in the models.
Well done, this is a tricky subject but is an integral part of modern modems.
30 Apr 2005
21 Apr 2005
Can I get it for matlab R13 please. Need it to see wether it is better then my approch or the same
13 Apr 2005
saifudeen a r
20 Jan 2005
now it is good
only what is about fading and AGC joint working with synchronization, if it is added, it will be real channel simulation
20 Jan 2005
looks good, but I can not run it, the error is
Failed to find 'Direct-Form II Transpose Filter' in library 'dspobslib' referenced by 'timing_recovery_1/Timing Error Detector + Loop Filter. Requires 4 samples per symbol. /Timing Error Detector/Loop Filter /Direct-Form II Transpose Filter2'
13 Feb 2009
New discrete time TX model added and files updated for r2007b and are compatible with 2008a and 2008b as well.
08 Jan 2010
Updated for R2009B
30 May 2013
This update generalizes the previous QPSK models to support N QAM, QPSK being a subset of N QAM. It is also compliant with R2012a,R2012b,R2013a.
26 Sep 2013
Models updated for compliance with changes in R2013B.