On Wed, Jul 23, 2008 at 10:43 PM, Jason U. [email protected]
What is the best way to measure the channel for use in space-time
coding schemes using an RFX2400 board?
As far as I know you can only get the I and Q streams out of the USRP,
and I’m not sure how you would get a set of channel coefficients.
Are you trying to measure the impulse response of the channel? If so,
one technique would be to transmit a known pseudo-random bit sequence
m-sequence) using BPSK modulation at the carrier frequency of interest.
chip rate of the sequence determines the measurement system bandwidth,
the sequence length determines the ‘dynamic range’ of the measurement.
At the receiver set the LO to the same carrier frequency as that at the
transmitter. Here you need to cross-correlate the equivalent low-pass
received signal with the known m-sequence to give the (complex) impulse
response of the channel. Any ‘peaks’ that exceed your definition of a
threshold noise level would be your channel coefficients in the time