How can I generate OFFSET binary code for an input signal that I can modulate and transmit in Communications System Toolbox 5.0 (R2011a) ?

I would like to generate an OFFSET BINARY code which can be modulated using an M-PSK modulator block in Communications System Toolbox.

Prior to the modulation step, I would like to generate an OFFSET BINARY code using our source blocks.

The OFFSET BINARY sequence is as described on the link below:

https://en.wikipedia.org/wiki/Offset_binary

Answer 1

[MathWorks Support Team]

We do not have a specific block that helps generate OFFSET binary code for a given input signal. Refer to the attached model that demonstrates generating an OFFSET binary code for a 4-ary number using Simulink blocks.

The problem can be solved by noting that the conversion from 2's compliment to OFFSET binary can be carried out by inverting the MSB. The attached model show one way of doing it. After the Integer to Bit Converter block, the MSB element of the output vector is selected and negated, then recombined with the other output bits.