High capacity techniques for tactical mobile networks

Authors:

  • Kia Wiklundh
  • Sara Linder
  • Ulf Sterner

Publish date: 2010-12-27

Report number: FOI-R--3074--SE

Pages: 27

Written in: Swedish

Keywords:

  • MIMO
  • transmit diversity
  • spatiell multiplexing
  • adaptive coding and modulation
  • network simulation
  • adaptive data rate
  • ad hoc network
  • tactical network
  • channel model

Abstract

There is a need for higher data rates in many new radio systems as well as in future military radio systems. Several promising techniques to achieve an enhanced capacity have also been introduced in many new civilian standards. It is, however, not possible to just incorporate these techniques directly in military radio systems, since there are fundamental differences in the base assumptions compared to civilian systems. To be able to incorporate high capacity techniques in tactical mobile networks, a number of questions need to be answered. The purpose of this work is to find solutions of some of this questions. In this report, a suitable multiple-input multiple-output (MIMO)-algorithm is presented and the gain compared to a single antenna system is shown, for a military scenario for the frequency band around 300 MHz. It is shown that transmit diversity has better performance than several other more complex algorithms. It is suggested that MIMO antennas should be used on vehicles for this frequency band. In the report, a new developed channel model with low computational complexity is presented, suitable for network simulations. The purpose of the model is to evaluate e.g. high capacity techniques in communication networks. The model shows a much better agreement with measurement data than earlier models for network simulations. This reduces the risk for incorrect conclusions. Another promising technique to increase the capacity is adaptive coding and modulation, which yields an adaptive data rate. In the report, a discussion is held concerning what needs to be modified if this technique should be implemented in tactical ad hoc networks. Adaptive data links require good information of the link channel status and require mainly modifications of the MAC layer.