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measuring Baudrate from QPSK signals

Started by bochao76 November 9, 2006
Good morning,

does anybody has an idea, how to measure the baudrate also known as
the symbolrate of a QPSK signal - I have a Real-Array and an
Imag-Array of data-streams?

1. How should I proceed?
2. Is finding zero-crossing from the signal a good approach?
3. Does anybody has source-code concerning this .

Thanx a lot in advance for your support. Best regards.

Bochao
The real and imaginary numbers in the array form the composite QPSK symbol as
Real + i*Imag. This makes one symbol. So your baud rate is as many [Real + i*Imag] symbols you send in a second. Also refer to this entry on Wikipedia http://en.wikipedia.org/wiki/Baud

bochao76 wrote:
Good morning,

does anybody has an idea, how to measure the baudrate also known as
the symbolrate of a QPSK signal - I have a Real-Array and an
Imag-Array of data-streams?

1. How should I proceed?
2. Is finding zero-crossing from the signal a good approach?
3. Does anybody has source-code concerning this .

Thanx a lot in advance for your support. Best regards.

Bochao
For timing recovery (equivalent to determination of symbol-rate) in AWGN
look at

*A BPSK/QPSK Timing-Error Detector for Sampled Receivers*
Gardner, F.;
Communications, IEEE Transactions on [legacy, pre -
1988]
Volume 34, Issue 5, May 1986 Page(s):423 - 429
Nandan
On 11/9/06, Amit Pathania wrote:
>
> The real and imaginary numbers in the array form the composite QPSK symbol
> as
> Real + i*Imag. This makes one symbol. So your baud rate is as many [Real
> + i*Imag] symbols you send in a second. Also refer to this entry on
> Wikipedia http://en.wikipedia.org/wiki/Baud
>
> bochao76 wrote:
> Good morning,
>
> does anybody has an idea, how to measure the baudrate also known as
> the symbolrate of a QPSK signal - I have a Real-Array and an
> Imag-Array of data-streams?
>
> 1. How should I proceed?
> 2. Is finding zero-crossing from the signal a good approach?
> 3. Does anybody has source-code concerning this .
>
> Thanx a lot in advance for your support. Best regards.
>
> Bochao
>