This project has been realized at Itron, the former Schlumberger department between 2011 and 2016.
The domain of Itron activity is gaz/water/electricity metering. Right now the smart grids are used. So the products are gaz/water/electricity counters.
This industry suppose to make two parts of the activity: (1)- metering itself – counting water cubes, kilowatts consumptions and (2) – transition of this information to base station.
The most part of communication for 3 meters are carried out with wireless communication, and the electrical meters could use the CPL communication: via the electricity network.
Technical realization of project.
The legacy counters used only the GMSK based modulation. When the new smart grids use the recently approved IEEE 802.15.4.g standard. It includes 3 types of communication: legacy compatible GFSK, long range high sensitivity modulation DSSS and OFDM based for high bit rate information channels.
GFSK could have some reference to 2G mobile modulation, DSSS with spread spectrum – to 3G (though, CDMA is not exactly the same technique) and OFDM – to 4G (LTE).
Main objective of this project was to replace the legacy modulation GFSK with all the available techniques in ZigBee standard for smart grids: IEEE 802.15.4g. The PHY (physical layer has been integrated from the provider (TI) with some modifications and adaptations. The card was implemented also in Itron, including the integration and modification of RF part. Protocol layer has been implemented by team as well. The entire test bank, RF tests, simulation of all three modulations has been realized in company.
My participation in project.
The following actions have been realized during my 4 years:
- DSP algorithms design. DSP real-time code analysis/ reveres engineering & development (Texas Instruments).
- Signals processing simulation: FSK modulator-demodulator, reverse engineering of DSSS (spread spectrum signals), equalizers, OFDM simulation, synchronization, re-sampling, interpolation.
- Presentations for the team the mathematics and signals processing algorithms, real time reverse engineering schemes, on the themes of DSP & telecommunication,
- Bibliographic review
- Specifications development
- Development of simulator of multipath propagation models.
- Implementation of test tool Tx / RF – Rx / carte DSP in real time with GUI and PSR adaptive calculations.
Environment and techniques used in project.
Environment: Matlab, C, Asm, DSP TI Soprano, Code Composer Studio, Atmel DSP, Agilent RF generator, ACPR (adjacent channel power ratio) tests
Technics:
- Frequency, phase burst synchronization
- AGC
- Coherent and non-coherent detection
- GFSK, DSSS, OFDM demodulation
- Resampling
- Equalizing
- Test tool with GUI creation under Matlab
- Optimization and profiling the C towards assembl
Main results.
- Performance of developed FSK simulator estgives the equivalent PSR to the real time code of Texas Instruments
- Multiple signals processing presentations have clarified a lot of technical point for the team
- Propagation model gives the correct results of receiving power
- Multiple RF tests have been carried out
- Automation of RF test bench gave the efficient visualization of different tests results
