Re: [Discuss-gnuradio] Spread Spectrum question in gnuradio

[Johnathan Corgan]

On Tue, Apr 27, 2010 at 21:19, John Andrews <address@hidden> wrote:

> If I want to transmit a signal which is DSSS spread using BPSK. Is it
> correct for me to first digitally spread the incoming data bits and then
> apply BPSK before sending it to the USRP or should I first convert the
> signal to BPSK and then multiply the output of the BPSK modulator with the
> PN sequence although I don't know how to do it.

Technically, these are equivalent.  However, it is easier and uses
less CPU to XOR your data sequence with your PN code, then send it to
the modulator.

Johnathan