The ranging error influence on channel capacity in geostationary orbiting satellite collocation systems

In order to improve the capacity of satellite communication systems caused by limited geostationary orbit (GEO) resource, cooperative transmission is widely used in GEO satellite collocation systems. However, due to technical limitations, the ranging error cannot be completely eliminated, which may induce relatively large variance of channel capacity. Current analysis methods are usually based on the error forming mechanism with prohibitively high complexity. In this paper, an analysis method based on the Shannon channel capacity is proposed. Through the probability statistics theory and error transfer formula, the probability density function (PDF) of ranging error and the maximum value of channel capacity are derived to provide a practical parameter selection strategy that satisfies the expected minimum variance of channel capacity. Simulation results show that with the purpose of achieving the maximum channel capacity as well as reducing the error, the ranging error should be within 7cm. In addition to increasing the accuracy of user selection, it could also be valuable to raise carrier frequency appropriately.