[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q
From: |
njm25 |
Subject: |
Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q |
Date: |
Wed, 21 Mar 2007 17:31:36 -0400 |
Thanks again for the help. I think I better understand how to set the RX mux.
I am now working on the multi_file.py example to receive using 2 daughterboards
on the same USRP. I want to do the same type of thing using 2 antennas where
RX-A and RX-B (on side A) will receive signal 1's I and Q and RX-A and RX-B (on
side B) will receive signal 2's I and Q. If my understanding is correct, I
would set the mux to (0x32103210). Let me know if this is not correct.
My question now comes on the TX side. I don't quite understand how to set the
TX mux. I want to transmit using 2 daughterboards on 1 USRP so I am using the
fm_tx_2_daughterboards.py example. I want daughterboard 1 to transmit the I
(RX-A) and Q (RX-B) of signal 1 and daughterboard 2 to transmit the I (RX-A)
and Q (RX-B) of signal 2. This example uses the command:
self.u.set_mux(0xba98)
which I don't think is right for what I want to do, but I don't really
understand how to set the TX mux in the same way I understand how to set the RX
mux (it seems to be different). How would I set the TX mux to do what I want?
Thanks
Nick
----- Original Message -----
From: Eric Blossom <address@hidden>
Date: Tuesday, March 20, 2007 10:15 am
Subject: Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q
> On Sun, Mar 18, 2007 at 02:46:26PM -0400, address@hidden wrote:
>
> > It's a little confusing to me why the Basic TX does not have a
> > problem using both the I and Q channel but the Basic RX does.
>
> Actually, there's no problem. You can get it to do what you want
> by explicitly specifying the rx mux value.
>
> To feed both A side inputs into the DDC 0 as I & Q, do
>
> u.set_mux(0x10101010)
>
> /*!
> * \brief Set input mux configuration.
> *
> * This determines which ADC (or constant zero) is connected to
> * each DDC input. There are 4 DDCs. Each has two inputs.
> *
> * <pre>
> * Mux value:
> *
> * 3 2 1
>
> * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
> 1 0
> * +-------+-------+-------+-------+-------+-------+-------+-----
> --+
> * | Q3 | I3 | Q2 | I2 | Q1 | I1 | Q0 |
> I0 |
> * +-------+-------+-------+-------+-------+-------+-------+-----
> --+
> *
> * Each 4-bit I field is either 0,1,2,3
> * Each 4-bit Q field is either 0,1,2,3 or 0xf (input is const zero)
> * All Q's must be 0xf or none of them may be 0xf
> * </pre>
> */
> bool set_mux (int mux);
>
>
>
> > It seems to me that the command "-R a:1" would tell the RX_B
> input to
> > receive but not the RX_A input anymore. I need both the inputs to
> > receive data at the same time, as I/Q channels connected to my RF
> > front end. Any insights in how I do this would be much appreciated
> > (if my assumption that "-R a:1" would only have the RX_B input
> > receive).
>
> > Thanks
> > Nick
>
> Eric
>
- Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q, njm25, 2007/03/16
- Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q, njm25, 2007/03/18
- Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q, njm25, 2007/03/20
- Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q,
njm25 <=
- Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q, njm25, 2007/03/26