This version (04 Feb 2021 15:16) was approved by Michael Hennerich.The Previously approved version (25 May 2019 16:08) is available.
Table of Contents
ADALM-PLUTO Receive
Receive Architecture
The AD9363 receive chain is based on Direct Conversion technique. Although this block diagram is for the AD9361, it is also appropriate for the AD9363 found inside the ADALM-PLUTO. The difference between the two units is the tuning range, a minor missing features (DCXO, external LO are missing and the RF channel bandwidth is reduced).
Some things to think about:
- AGC is good. Please use it.
- AGC needs to be set up properly so that it is good, defaults are just that - a best guess for generic waveforms.
- Half bands and FIR is there, you should use those.
- The best performance is normally running the ADC as fast as possible, and decimating as much as possible.
Receive Performance
Details on the performance can be found in the performance section.
While there are many aspects of receive performance, the two most common are:
- Receiver sensitivity (how far away can I be, and still receive something). Separate Topic.
- Input fidelity (how accurate is the reception)
For the ADALM-PLUTO, both the receiver sensitivity and input accuracy are frequency dependent. For plots vs frequency, check out the detailed performance section.
This is the output of the Keysight 89600 VSA software, which is used to measure signal demodulation and complete vector signal analysis. In this case, we generate an LTE 10 (10MHz wide channel), and transmit it out the Tx port of the E4438C ESG Vector Signal Generator and capture it on the ADALM-PLUTO's Rx port, and then save the data, and load it into the VSA software for analysis. We can measure the RF offset (frequency error = 67Hz), and how accurate the 64-QAM constellation is created (an EVM of -43 dB, or less than 0.6% RMS error) - which is pretty good (better than the AD9363 datasheet).
By changing the LO frequency, output power, output attenuation, these results will change.
university/tools/pluto/users/receive.txt · Last modified: 01 Feb 2021 13:33 by Iulia Moldovan