[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] QPSK with direct-sequence spread spectrum
From: |
Peter Massam |
Subject: |
Re: [Discuss-gnuradio] QPSK with direct-sequence spread spectrum |
Date: |
Mon, 31 Oct 2011 10:59:06 -0700 (PDT) |
In general you're right, but it depends on the details. Its usually quite
straightforward, but a common mistake is to use the wrong bit-to-symbol
mapping. 0 -> +1 and 1 -> -1 means that an XOR applied to bits is
equivalent to multiplication applied to symbols.
Nowlan, Sean wrote:
>
> Hi all,
>
> I'm wondering if spreading a bitstream (XOR-ing each bit with
> SPREAD_FACTOR bits of sequence) before QPSK modulation is equivalent to
> operating on the modulated stream, i.e., multiplying the complex output
> with -1's and 1's from the sequence. So far I can't get the math to work
> out. Any suggestions?
>
> Thanks,
> Sean
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
--
View this message in context:
http://old.nabble.com/QPSK-with-direct-sequence-spread-spectrum-tp32752034p32754111.html
Sent from the GnuRadio mailing list archive at Nabble.com.