diff --git a/lab_5/leo_satellite_pass.md b/lab_5/leo_satellite_pass.md index 60ce072..a3842ae 100644 --- a/lab_5/leo_satellite_pass.md +++ b/lab_5/leo_satellite_pass.md @@ -1,11 +1,3 @@ - -

Lab 5 - Wireless Networking Technologies

@@ -58,7 +50,7 @@ by Timo Niemann | Pilot tracking | not used | default receiver behavior | - | disabled | - | - | | Receiver CFO correction | not used | coarse and fine preamble-based CFO correction active | - | - | - | - | - +
### Task1 @@ -74,7 +66,7 @@ To calculate the distance to the satellite, the MATLAB access analysis example w The first satellite flyby occurs at around 08:05:30. During the pass, the distance first decreases as the satellite approaches the ground station and then increases again after the closest approach. Around 08:53:30 to 08:54:00, the distance reaches a maximum because the satellite is on the far side of its orbit relative to the ground station. The second pass occurs at around 09:42. Its minimum distance is larger than during the first pass because Earth's rotation changes the relative position of the ground station below the satellite orbit. - +
#### 1.3 @@ -82,7 +74,7 @@ The first satellite flyby occurs at around 08:05:30. During the pass, the distan As in the distance plot, the elevation angle reaches its highest value during the first pass. The second pass has a lower maximum elevation because Earth's rotation shifts the ground station relative to the satellite ground track. - +
### Task2 @@ -243,7 +235,7 @@ requiredAntennaGain = max(requiredTxPower - amplifiedTxPower, 0); With the 30dB amplifier, the remaining required antenna gain is between 30.99dB and 57.54dB. - +
### Task3 @@ -253,12 +245,16 @@ With the 30dB amplifier, the remaining required antenna gain is between 30.99dB Using the previously set transmit power of 20 dBm, the graph is identical to the receive power plot from task 2.2, because the receiver is the ground station. The received power remains below both the -85 dBm detection threshold and the -75 dBm reliable reception threshold. Therefore, WiFi packet reception is not possible during the simulated pass with normal WiFi transmit power. +
+ #### 3.2 ![satellite visibility over time plot](sat_visibility_over_time.svg) The visibility was extracted from the access analysis. MATLAB's `dopplershift` function returns no finite value when the satellite is not visible to the ground station. The plot shows that the satellite is visible from about 08:00 to 08:12 and again from about 09:37 to 09:48. The ground station therefore has a total satellite visibility of about 23 minutes during the two-hour simulation. +
+ #### 3.3 ![Doppler shift over time plot](doppler_shift_over_time_x_visibility.svg) @@ -267,7 +263,7 @@ The blue line shows the Doppler shift returned by MATLAB's `dopplershift` functi In this scenario, Doppler shift can support localization because it constrains the relative radial motion between satellite and ground station. However, Doppler alone is not sufficient for unique localization: the satellite orbit, time, and additional measurements such as range or elevation are still required. - +
### Task4 @@ -281,7 +277,7 @@ Only small differences between the curves are visible. The maximum PER differenc A likely reason is that the 802.11 receiver still performs coarse and fine CFO correction using the WiFi preamble. Pilot tracking is disabled as required by the task, but the preamble-based CFO correction is still active. Because of this, even the case without transmitter-side pre-compensation can still decode many packets successfully. The additional benefit of ideal pre-compensation is therefore limited at the simulated 2.4 GHz carrier frequency. - +
#### 4.4 diff --git a/lab_5/leo_satellite_pass.pdf b/lab_5/leo_satellite_pass.pdf new file mode 100644 index 0000000..0cc453b Binary files /dev/null and b/lab_5/leo_satellite_pass.pdf differ