Adaptive Channel Allocation for TACS
Jan Lundequist and
Master Thesis, Report UPTEC 95048E, 74 pp,
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.
- Ericsson Radio Systems AB
- Thesis Advisor:
- Mikael Sternad
- Related publications:
paper based on this work.
- Related Master Thesis
on adaptive SAT allocation for TACS.