ECE4253 Digital Communications | |

Department of Electrical and Computer Engineering - University of New Brunswick, Fredericton, NB, Canada | |

This online tool encodes an input string into a Data Matrix 2D symbol as defined by the *ISO/IEC 16022:2006* standard.

Data Matrix symbols are two dimensional bar codes arranged as distinctive square matrices with various dimensions according to their data capacity. The Data Matrix symbol produced here is a (14 × 14) matrix that carries eighteen bytes including eight data bytes.

A Data Matrix symbol incorporates many elements of a digital communications system including timing reference, interleaving, data compression, and the use of powerful error correction. Reed Solomon GF(256) error correction is used such that the symbol below holds 8 data bytes in a RS (18,8) code.

3 | . | 1 | 4 | 1 | 5 | 9 | 2 | 6 | 5 | 3 | 5 | 8 | 9 |

The (14 × 14) Data Matrix can carry eight bytes of information. Using the ASCII data format, each byte can be:

- A single 7-bit ASCII character occupying one byte as the character plus 1.
For example, the ASCII character 'A' = 0x41 = 64 (decimal) is stored as 64 + 1 = 65 = 0x42.

- A pair of digits occupying one byte coded as packed BCD plus 130 (decimal) = 0x82
For example, the digits '99' are stored as 99 + 130 = 229 = 0xE5.

- As required the byte 0x81 = 129 indicates
*end of message*.

The input text provided: "3.141592653589" was coded into eight bytes as:

msg = [ 52 47 144 145 222 195 165 219 ];

The remaining bytes in the symbol are computed to provide error correction. (See MATLAB)

2024-07-14 16:55:59 ADT
Last Updated: 2023-12-17 |
Richard Tervo [ tervo@unb.ca ] | Back to the course homepage... |