A Synchronized Mil-Std-188-110B Receiver

Extends the shipping "188" modem. Features a synchronized 1200 bps / short interleave receiver.

Description

This file set includes a top level unsychronized Tx / Rx model and a more detailed synchronized Rx model. The top level model Tx outptut has been tested with a third party reference mil-std-188-110 modem and found to generates compliant waveforms. A variable symbol rate Tx driving the synchronized Rx model was added on 11/21/08.

The Rx model implements the 1200 bps / short (0.6 sec) interleave mode. It is driven by recorded wave files that have varying degrees of timing and carrier errors to test the tracking loops.

The model includes:
1) selectable channel impairments
2) preamble correlation to initiate downstream processing
3) a 20 forward-20 feedback tap Recursive Decision Feedback Equalizer
3) timing recovery loop to track long term clock rate errors
4) carrier recvoery loop to ease the burdon of the equalizer
5) novel timing and phase error detectors
6) received data converted to scrolling text output

Acknowledgements

The author wishes to acknowledge the following in the creation of this submission:
Defense Communications: US MIL-STD-188-110B Waveform Simulation

• Required Products: Communications Blockset; Communications System Toolbox; DSP System Toolbox; Signal Processing Toolbox; Simulink; Stateflow
• MATLAB release: MATLAB 7.9 (2009b)
• Other requirements: Windows audio support.

[sandeep mane]

quite useful. Thanks.

[Tanyer Alan]

 

[Ben]

This model is very useful. Could the author or someone else give a detailed discussion about the timing and carrier recovery algorithm used in this model?