diff options
| author | Nicholas Corgan <nick.corgan@ettus.com> | 2012-12-18 15:47:17 -0800 |
|---|---|---|
| committer | Nicholas Corgan <nick.corgan@ettus.com> | 2012-12-18 15:49:13 -0800 |
| commit | 2acddaccbde707afe8c28f183bb4418947384786 (patch) | |
| tree | 7d1390a5a72fec7793bec7c5a12b0b5873de4cbc /host/docs/sync.rst | |
| parent | 9761065040e56e43a05b69e5e41ca66e4175ee8d (diff) | |
| download | uhd-2acddaccbde707afe8c28f183bb4418947384786.tar.gz uhd-2acddaccbde707afe8c28f183bb4418947384786.tar.bz2 uhd-2acddaccbde707afe8c28f183bb4418947384786.zip | |
docs: UHD/USRP rephrasing
Diffstat (limited to 'host/docs/sync.rst')
| -rw-r--r-- | host/docs/sync.rst | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/host/docs/sync.rst b/host/docs/sync.rst index 8622dc642..a1f6cb7df 100644 --- a/host/docs/sync.rst +++ b/host/docs/sync.rst @@ -4,9 +4,9 @@ UHD - Synchronization Application Notes .. contents:: Table of Contents -The following application notes explain how to synchronize multiple USRPs -with the goal of transmitting or receiving time-aligned samples for MIMO -or other applications requiring multiple USRPs operating synchronously. +The following application notes explain how to synchronize multiple USRP +devices with the goal of transmitting or receiving time-aligned samples for MIMO +or other applications requiring multiple USRP devices operating synchronously. **Note:** The following synchronization notes do not apply to USRP1, which does not support the advanced features available in newer products. @@ -14,7 +14,7 @@ which does not support the advanced features available in newer products. ------------------------------------------------------------------------ Common Reference Signals ------------------------------------------------------------------------ -USRPs take two reference signals in order to synchronize clocks and time: +USRP devices take two reference signals in order to synchronize clocks and time: * A 10MHz reference to provide a single frequency reference for both devices. * A pulse-per-second (PPS) to synchronize the sample time across devices. @@ -103,16 +103,16 @@ and the user can also parse this string to determine GPS time: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Method 3 - internal GPSDO ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -USRPs with internal GPSDOs properly configured will automatically +USRP devices with internal GPSDOs properly configured will automatically configure themselves to set the VITA time to current UTC time. See the `GPSDO Application Notes <./gpsdo.html>`_ for more details. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Method 4 - MIMO cable ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -A USRP can synchronize its time to another USRP via the MIMO cable. +A USRP device can synchronize its time to another USRP device via the MIMO cable. Unlike the other methods, this does not use a real "pulse per second". -Rather, the USRP sends an encoded time message over the MIMO cable. +Rather, the USRP device sends an encoded time message over the MIMO cable. The slave device will automatically synchronize to the time on the master device. See the `MIMO Cable Application Notes <./usrp2.html#using-the-mimo-cable>`_ for more detail. @@ -123,7 +123,7 @@ Synchronizing Channel Phase ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Align CORDICs in the DSP ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -In order to achieve phase alignment between USRPs, the CORDICS in both +In order to achieve phase alignment between USRP devices, the CORDICS in both devices must be aligned with respect to each other. This is easily achieved by issuing stream commands with a time spec property, which instructs the streaming to begin at a specified time. Since the devices are already |