Adaptive Channel Allocation for TACS

Jan Lundequist and Björn Hansson,

Master Thesis, Report UPTEC 95048E, 74 pp, March 1995.

Abstract:

An ACA (Adaptive Channel Allocation) scheme is descried and its applicability to a TACS mobile communication system using directional antennas is studied.

The objective of ACA is to improve system performance in terms of capacity and speech quality. Frequency planning of voice channels is automated and co-channel interference levels are minimized.

The proposed scheme is divided into two algorithms. The FRA (Frequency Re-Allocation) algorithm performs the frequency planning and allocates voice channel sets to each cell on a long term basis. The QDCS (Quality Driven Channel Selection) algorithm handles the voice channel assignment on a per call basis. Cost functions that weigh different system properties together in a scalar measure have been used in both algorithms. Results show that the ACA concept is applicable to TACS, and that system performance improves significantly in spite f the fact that the state in the downlinks is unknown in the TACS system.

Typically, the capacity can be increased by at least 50 percent as compared to a system using a fixed 7/21 cell plan with maintained speech quality. Results show that the QDCS algorithm can be used without the FRA algorithm but that the converse may not be possible. A proposed power control algorithm based on path gain that aims at achieving a strong correlation between crosslinks in the system is analyzed. General performance characteristics are examined and specific numerical results are presented.

Company:

Ericsson Radio Systems AB

Thesis Advisor:

Mikael Sternad

Related publications:

Globecom'95 paper based on this work.

Related Master Thesis on adaptive SAT allocation for TACS.