From d9834b84f4e141a4ed0befcdbc814ab5148807e1 Mon Sep 17 00:00:00 2001 From: Martin Braun Date: Tue, 8 Mar 2022 17:44:26 +0100 Subject: docs: n3xx: Add info on customizable band edges and gain profiles --- host/docs/usrp_n3xx.dox | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/host/docs/usrp_n3xx.dox b/host/docs/usrp_n3xx.dox index e96a37494..8ee0d4627 100644 --- a/host/docs/usrp_n3xx.dox +++ b/host/docs/usrp_n3xx.dox @@ -455,6 +455,10 @@ For a list of which arguments can be passed into make(), see Section rx_lo_source | Initialize the source for the RX LO. | N310 | rx_lo_source=external tx_lo_source | Initialize the source for the TX LO. | N310 | tx_lo_source=external rfic_digital_loopback | Digital data loopback inside the RFIC. | N310 | rfic_digital_loopback=1 + tx_gain_profile | Initialize device with a specific TX gain profile. | N310 | tx_gain_profile=manual + rx_gain_profile | Initialize device with a specific RX gain profile. | N310 | rx_gain_profile=manual + tx_band_map | Semicolon-separated list of TX band edges. | N310 | tx_band_map=0.0;723.18e6;1623.18e6;3323.18e6 + rx_band_map | Semicolon-separated list of RX band edges. | N310 | rx_band_map=0.0;431e6;601e6;1051e6;1601e6;2101e6;2701e6 \subsection n3xx_usage_init Device Initialization @@ -1345,6 +1349,47 @@ For example, to set your device to auto-boot, with TPM, the flag value is 0x1, s $ eeprom-set-flags 0x1 +\subsection n3xx_mg_gain_profiles Gain Profiles + +The N310 supports four gain profiles: `default`, `manual`, +`default_rf_filter_bypass_always_on`, and `default_rf_filter_bypass_always_off`. + +Usually, UHD will program individual gain components to create an overall gain +that is selected. The N310 daughterboards have three gain stages per path (two +digital step attenuators (DSAs), and one amplifier). When using the `manual` +profile, the DSAs and amplifiers can be programmed directly. In the other gain +profiles, a single, overall gain can be given, and UHD will attempt to program +the gain stages based on hard-coded gain tables. The difference between the +three "default" profiles is how the amplifier is used: Either it is always on, +always off, or it is switched on and off to optimize linearity. + +\subsection n3xx_mg_custom_band_edges Custom Band Edges + +\b Note: This is a highly advanced feature. Most users will not have to use this! + +The N310 daughterboard splits the TX and RX paths into 4 and 7 different bands, +respectively, to hardware-optimize the RF fidelity at all available frequencies. + +See the [schematics](https://kb.ettus.com/N300/N310#Schematics) for more details. + +Using the `rx_band_map` and `tx_band_map` device args, it is possible to move +the band edges in software. This may be useful if the hardware was modified to +use different filters, for example, because a signal of interest always falls +onto a band edge. Using the `tx_band_map` or `rx_band_map` device arguments, +you can provide a list of lower band edges for every band. Make sure to provide +4 (for Tx) or 7 (for Rx) floating-point values. The first value should always be +zero (0.0). It may make sense to encode these values in your `uhd.conf` file: + +~~~{.ini} +[type=n3xx] +rx_gain_profile=default_rf_filter_bypass_always_off +tx_gain_profile=default_rf_filter_bypass_always_on +rx_band_map=0.0;431e6;601e6;1051e6;1601e6;2101e6;2701e6 +tx_band_map=0.0;723.18e6;1623.18e6;3323.18e6 +~~~ + +In this example, the second Rx band would start at 431 MHz. + \section n3xx_rh N32x-specific Features \subsection n3xx_rh_panels Front and Rear Panel -- cgit v1.2.3