= TRF6151C =
This is the Texas Instruments RF Chip TRF6151C (Rita)
It includes a VCO, Mixers, etc.
Data sheet is available from http://www.52rd.com/bbs/Detail_RD.BBS_8719_68_1_1.html but registration to the chinese forum
is required for download.
The TSP to the TRF6151 uses three wires: * CLOCK (regular CLK_13M) * STROBE (generated by TPU) * DATA (provided by TPU at falling edge of CLOCK, TRF samples data at rising edge of CLOCK)
[[Image(Rita:trf6151_tsp.png)]]Analog I/Q baseband output
During development I've taken some measurements of the I/Q output of the TRF6151.
The green and black graph of the diagrams below are the "I" channel positive and negative signal.
The magenta graph is the difference signal computed by the Scope.
=== baseband output in idle mode listening on paging channel ===
This is zoomed out to a very long timebae to see the Rx activity at 1.8 second intervals,
which apparently was the paging channel for the paging group of that IMSI.
=== multiple consecutive bursts ===
This shows multiple consecutive received bursts.
You can see that there is a DC offset when the TRF6151 is powered up, but you can't really see data on that DC offset
=== a single burst ===
=== bits of a burst ===