LTE IoT Network Synchronization
Cellular standards and networks have traditionally been optimized for the high throughput requirements of modern smartphones. Recently the Internet of Things (IoT) has emerged as a new application with vastly different requirements. Ericsson predicts, that there will be 15 billion smart devices with Internet connectivity. Potential applications include smart metering, tracking in logistics, environmental sensing, and smart buildings. Two new variants of LTE have been standardized as part of Release 13 in 2016 for this kind of device: LTE Cat-M1 (eMTC) and NB-IoT. They both offer reduced cost and power consumption, as well as improved coverage, but Cat-M1 supports more features and has a higher maximum throughput. As part of our communication platform, we are currently developing a modem, which supports both standards, at IIS.
Network synchronization is the first step in the communication between the user equipment (UE) and the base station. It consists of the UE looking for the LTE carrier, correcting for a local time and frequency offset and the acquisition of the most important information about the LTE carrier. The increased coverage requirements imply that the noise power is much larger than the signal power (SNR: -12.9dB), making the network synchronization very challenging.
In LTE the network synchronization consists of:
- Detecting the Primary Synchronization Sequence
- Detecting the Secondary Synchronization Sequence
- Decoding the Physical Broadcast Channel (PBCH) to receive the Master Information Block (MIB)
Several different methods to improve the decoding of the PBCH have been proposed. A new instance of the PBCH is sent every 40 ms. One method is to combine the received data past this 40ms border, even though the data changes between repetitions .
During this project, algorithms for the PBCH decoding for LTE Cat-M1 shall be studied, evaluated and implemented. Their performance can be verified in the existing LTE Matlab framework, before they are implemented in hardware and/or software. The hardware implementation can be done in High Level Synthesis (HLS) or VHDL and verified on an FPGA testbed. It's also possible to modify the task within the topic of LTE Cat-M1 network synchronization based on the number of students and their preferences.
- Looking for 1-2 Semester/Master students
- Contact: Stefan Lippuner
- VLSI I
- 40% Theory, Algorithms and Simulation
- 40% Hardware/Software Co-Design (C, HLS/VHDL)
- 20% FPGA Verification
 3GPP. Release 13. http://www.3gpp.org/release-13, 2016.
 Qualcomm. Paving the path to Narrowband 5G with LTE Internet of Things (IoT), 2016
 3GPP/Ericsson. R1-152190 PBCH repetition for MTC, 2015