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author | dburgess <dburgess@19bc5d8c-e614-43d4-8b26-e1612bc8e597> | 2011-10-12 07:44:40 +0000 |
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committer | dburgess <dburgess@19bc5d8c-e614-43d4-8b26-e1612bc8e597> | 2011-10-12 07:44:40 +0000 |
commit | b3a0ca42db0bd08c58b9370a1398528016e6953f (patch) | |
tree | 1e81558498b765f0faac4c8588c18fbc4bfc8dfb /Transceiver52M/README | |
parent | ec3d77d0eaa12c102893490766557dd4d4efd029 (diff) |
Adding in the missing Transceiver52M directory
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2307 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Diffstat (limited to 'Transceiver52M/README')
-rw-r--r-- | Transceiver52M/README | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Transceiver52M/README b/Transceiver52M/README new file mode 100644 index 0000000..491693c --- /dev/null +++ b/Transceiver52M/README @@ -0,0 +1,35 @@ +The Transceiver + +The transceiver consists of three modules: + --- transceiver + --- radioInterface + --- USRPDevice + +The USRPDevice module is basically a driver that reads/writes +packets to a USRP with two RFX900 daughterboards, board +A is the Tx chain and board B is the Rx chain. + +The radioInterface module is basically an interface b/w the +transceiver and the USRP. It operates the basestation clock +based upon the sample count of received USRP samples. Packets +from the USRP are queued and segmented into GSM bursts that are +passed up to the transceiver; bursts from the transceiver are +passed down to the USRP. + +The transceiver basically operates "layer 0" of the GSM stack, +performing the modulation, detection, and demodulation of GSM +bursts. It communicates with the GSM stack via three UDP sockets, +one socket for data, one for control messages, and one socket to +pass clocking information. The transceiver contains a priority +queue to sort to-be-transmitted bursts, and a filler table to fill +in timeslots that do not have bursts in the priority queue. The +transceiver tries to stay ahead of the basestation clock, adapting +its latency when underruns are reported by the radioInterface/USRP. +Received bursts (from the radioInterface) pass through a simple +energy detector, a RACH or midamble correlator, and a DFE-based demodulator. + +NOTE: There's a SWLOOPBACK #define statement, where the USRP is replaced +with a memory buffer. In this mode, data written to the USRP is actually stored +in a buffer, and read commands to the USRP simply pull data from this buffer. +This was very useful in early testing, and still may be useful in testing basic +Transceiver and radioInterface functionality. |