From 72dd1bb03dd9812c6f9cbe44278f013d0685d0fa Mon Sep 17 00:00:00 2001 From: Ben Hilburn Date: Tue, 25 Oct 2011 15:34:05 -0700 Subject: Adding stuff to the tune request docs. --- host/docs/general.rst | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/host/docs/general.rst b/host/docs/general.rst index e1c93b13a..aa6ac7aa0 100644 --- a/host/docs/general.rst +++ b/host/docs/general.rst @@ -16,12 +16,19 @@ A USRP device has two stages of tuning: * RF front-end: translates bewteen RF and IF * DSP: translates between IF and baseband -In a typical use-case, the user specifies an overall center frequency for the signal chain. -The RF front-end will be tuned as close as possible to the center frequency, -and the DSP will account for the error in tuning between target frequency and actual frequency. -The user may also explicitly control both stages of tuning through the tune_request_t object. - -Pseudo-code for tuning the receive chain: +In a typical use-case, the user specifies an overall center frequency for the +signal chain. The RF front-end will be tuned as close as possible to the center +frequency, and the DSP will account for the error in tuning between target +frequency and actual frequency. The user may also explicitly control both +stages of tuning through through the tune_request_t object, which allows for +more advanced tuning. + +In general, Using UHD's advanced tuning is highly recommended as it makes it +easy to move the DC component out of your band-of-interest. This can be done by +passing your desired LO offset to the tune_request_t object, and letting UHD +handle the rest. + +Tuning the receive chain: :: //tuning to a desired center frequency @@ -30,9 +37,8 @@ Pseudo-code for tuning the receive chain: --OR-- //advanced tuning with tune_request_t - uhd::tune_request_t tune_req; - tune_req.target_freq = my_frequency_in_hz; - //fill in tune request fields... + uhd::tune_request_t tune_req(my_frequency_in_hz, desired_lo_offset); + //fill in any additional/optional tune request fields... usrp->set_rx_freq(tune_req); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -- cgit v1.2.3