Last updated: January 15, 2009
The test set's base station emulator provides control over the following RF power levels:
Î
or
is defined in 3GPP TS 25.101 as the received power spectral density of the downlink as measured at the UE (mobile station) antenna connector. The downlink contains one or more downlink physical channels. The
Cell Power
setting sets the absolute level (in dBm) of the physical channels. The individual physical channel levels account for fractions of this setting, and are set in dB relative to the cell power (see
Downlink Channel Codes and Levels
). If you have accounted for path loss (see
Amplitude Offset
) between the test set output port and the UE antenna connector, then cell power is equivalent to Î
or
.
GPIB command: CALL:POWer
I oc is defined in 3GPP TS 25.101 as the power spectral density of a band-limited white noise source (simulating interference from other cells) as measured at the UE antenna connector. If you have accounted for path loss, then AWGN (Additive White Gaussian Noise) power is equivalent to I oc .
GPIB command: CALL:AWGNoise
I o is defined in 3GPP TS 25.101 as the total received power spectral density, including signal and interference, as measured at the UE antenna connector. The total RF power is the sum of cell power and AWGN power. If you have accounted for path loss, then total RF power is equivalent to I o .
GPIB command: CALL:TOTal:POWer[:AMPLitude]? (query only)
To access the cell power parameter using the test set's front panel, see How Do I Change Call Parameters? .
To access the AWGN power parameter using the test set's the front panel, How Do I Change Generator Information?
The power levels currently in use by the test set (as well as the "desired" levels) are displayed in the Generated Power Level Information window.
For the lab application only, the test set has the ability to simulate two individual cells (see Soft Handover ). In the lab application, the total RF power consists of Cell 1 power, Cell 2 power and the AWGN power if their states are on.
For the lab application, an external AWGN value is displayed when the test set is configured to generate faded forward channel signals with AWGN enabled. This setup requires a rear panel digital bus connection to an external PC running Baseband Studio software. For details, see Digital Bus Information .
The range of values that you can set these power levels to differs from the actual hardware range of the source. This is due to compensation for path loss between the test set RF output port and the UE antenna connector (see Amplitude Offset ).
For example, if you enter a value of -30 dBm for desired CW cell power, this indicates that you want -30 dBm of power at the UE antenna connector. So, if you have indicated an amplitude offset of -3.5 dB exists between the test set's RF In/Out port and the UE antenna connector, the source will actually have to output -26.5 dB in order to deliver -30 dB to the UE's antenna connector. Thus, with an amplitude offset of -3.5 dB, the settable range of CW cell power is -130.5 dB to -13.5 dB. The actual power range at a given time is defined by adding the value of the associated amplitude offset to the actual hardware range. If you select an invalid combination of power levels and amplitude offsets, an error message will appear at the bottom of the screen to alert you to this condition.
|
Actual Hardware Range with Amplitude Offset = 0 (RF In/Out Port) |
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Manual Operation: How Do I Change Generator Information?
Manual Operation: How Do I Change Call Parameters?