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LTE Downlink Base Station TX Test Bench
This example demonstrates:
LTE FDD Downlink TX, compliant with 3GPP specifications.
Specification document: TS 36.104, TS 36.211, TS 36.212
Configurable options include:
- NFramesSweep: number of 10ms frames used in each sweep
- FrameType: frame type and cycling preffix:
- 0: Frame structure type 1 / Normal CP: FDD
- 1: Frame structure type 2 / Normal CP: TDD
- 2: Frame structure type 1 / Extended CP: FDD
- 3: Frame structure type 2 / Extended CP: TDD
- MCS: modulation and coding scheme (change in LTE_DL_TSIG block parameters). Entries with two options relate to the setting of parameter MTBST � the first entry corresponds to Table 188.8.131.52-1 and the second one to Table 184.108.40.206-1A.
- N_RB_DL: number or resource blocks used for transmission
- Carrier Frequency (MHz)
- TxOutLvlStart, TxOutLvlSpan, TxOutLvlStep (dBm): Define swept power of transmitted signal
The test bench can be used to monitor:
- The CCDF at the input and output of DUT
- The TX signal spectrum at the input and output of DUT
- EVM %rms vs. output power
- The impact of phase noise on EVM
- The impact of phase/amplitude and DC offset on EVM
N_RB_DL defines the channel bandwith as defined in the specifications.
Note that the amplifier model is a behavioral model that can be replaced with the desired device, including an MWO circuit.
This example can be used to test a PA's error vector magnitude (EVM) performance vs. output power.
A reference IQ plot versus the measured IQ plot is shown. EVM measurements are calculated for each power level and plotted in the "EVM vs. Output Power" graph.
Please read the online help for information on any of the blocks that are used in the system diagrams. In addition, please read the online help for ACPR and EVM measurements.