Motivation

Satellites in the low-earth orbit (LEO) are moving with a high speed relative to the users on earth, which causes high Doppler shifts. Many communication systems, especially those using OFDM, are sensitive to Doppler shifts. Therefore, the Doppler shift has to be compensated.

Objective

The objective of this work is to answer the follwoing questions:

• How large is the Doppler shift for LEO satellites?
• How can the Doppler shift be compensated?
• How large is the influence of relativistic and gravitational effects on the Doppler shifts?
• Are classic approaches to compensate the Doppler shift suitable to compensate relativistics and gravitational Doppler shifts?

For Bachelor students the focus is on the classical Doppler shift due to the movement of satellites without relativistic effects.

Requirements

Good knowledge in mechanics,  wave propagation and general relativity as well as programming skills (preferable Matlab) are highly recommended.

Basic knowledge in wireless communication, statistics and signal processing will be helpful.