**Spring Quarter 2005-2006**

## EE 379B - Digital Communication II: Coding

Enhanced Dmin program for linear codes

This program may be used for the analysis of linear codes. Although its current form applies to convolutional codes, it may be adapted to also handle trellis coded modulation. Parameters computed include the minimum distance, the number of minimum distance paths (as well as the number of paths of subsequent distances), the number of bits in error corresponding to the minimum paths (as well as the number of bits in error corresponding to paths of subsequent distances), and the maximum length of paths corresponding to minimum distance (as well as the maximum length of paths corresponding to paths of subsequent distance).

Main module, dmin_main.m

Module initializing the state information, dmin_init.m. It is called by the main module.

Module performing a search iteration on the trellis, dmin_prop.m. It is called by the main module.

Function computing hamming distance, bdistance.m.

Function computing the next state and the output given a trellis representation, trellis_fn.m.

Function performing polynomial addition, polyadd.m.

Function converting generator matrix into trellis representation, trellis_gen.m.

Function converting matrix with elements with octal representation to matrix with elements with decimal representation, gen_convert.m.

Function converting parity matrix for code of rate 2/3 into trellis representation for systematic implementation, trellis_par23.m.

Function converting parity matrix for code of rate 3/4 into trellis representation for systematic implementation, trellis_par34.m.

Function converting parity matrix with elements with octal representation to matrix with binary elements, par_binconv.m.

Functions converting decimals into binary vectors, and binary vectors into decimals, dec2binm.m, binm2dec.m.

The following document contains the details of the algorithm, explains the usage of the program, and provides tables of parameters for convolutional codes: code_an.ps.

#### APP Program for Convolutional Code Decoding for AWGN Channel

Example with BPSK transmission of 64-state rate-1/2 802.11a std code over AWGN : test.m