Rita » History » Version 9
laforge, 02/21/2016 10:16 AM
1 | 8 | laforge | {{>toc}} |
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2 | 1 | laforge | |
3 | 8 | laforge | |
4 | h1. TRF6151C |
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6 | 6 | laforge | This is the Texas Instruments RF Chip TRF6151C (Rita) |
7 | 1 | laforge | |
8 | It includes a VCO, Mixers, etc. |
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9 | 6 | laforge | |
10 | Data sheet is available from http://www.52rd.com/bbs/Detail_RD.BBS_8719_68_1_1.html but registration to the chinese forum |
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11 | 1 | laforge | is required for download. |
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14 | 8 | laforge | h2. TSP |
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17 | 2 | laforge | The TSP to the TRF6151 uses three wires: |
18 | 8 | laforge | * CLOCK (regular CLK_13M) |
19 | * STROBE (generated by TPU) |
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20 | * DATA (provided by TPU at falling edge of CLOCK, TRF samples data at rising edge of CLOCK) |
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21 | 1 | laforge | |
22 | 9 | laforge | !Rita:trf6151_tsp.png! |
23 | 4 | laforge | |
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25 | 8 | laforge | h2. Analog I/Q baseband output |
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28 | 1 | laforge | During development I've taken some measurements of the I/Q output of the TRF6151. This signal |
29 | 8 | laforge | is fed to the [[TWL3025]] baseband ADC inputs. |
30 | 1 | laforge | |
31 | 7 | laforge | The green and black graph of the diagrams below are the "I" channel positive and negative signal. |
32 | 1 | laforge | The magenta graph (M1) is the difference signal computed by the Scope. |
33 | 7 | laforge | |
34 | 4 | laforge | All voltages have to be multiplied by a factor of 10, as 10:1 probes were used. |
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36 | 1 | laforge | |
37 | 8 | laforge | h3. baseband output in idle mode listening on paging channel |
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40 | 4 | laforge | This is zoomed out to a very long timebase to see the Rx activity at 1.8 second intervals, |
41 | which apparently was the paging channel for the paging group of that IMSI. |
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42 | |||
43 | 9 | laforge | !trf6151_iq_rx_paging_channel.png! |
44 | 1 | laforge | |
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46 | 8 | laforge | h3. multiple consecutive bursts |
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49 | 1 | laforge | This shows multiple consecutive received bursts. |
50 | 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 |
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51 | 4 | laforge | |
52 | 9 | laforge | !Rita:trf6151_iq_rx_burst_distance.png! |
53 | 4 | laforge | |
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55 | 8 | laforge | h3. a single burst |
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58 | 9 | laforge | !trf6151_rx_iq_one_burst.png! |
59 | 4 | laforge | |
60 | 8 | laforge | |
61 | h3. bits of a burst |
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63 | 1 | laforge | |
64 | 9 | laforge | !trf6151_rx_iq_bits_of_burst.png! |