Ray-tracing models

Ray-tracing models for:

• Indoor propagation
• Urban propagation
• Diversity and MIMO systems
• Distributed antenna systems or Macro-MIMO

Examine propagation environments in terms of:

• Field strengths
• Time delay: Delay Spread, Mean Excess Delay, Coherence Bandwidth, Power Delay Profiles
• Diversity Gain for Polarisation, Space, Frequency and Beam Sector diversity schemes under various Combining Strategies

Indoor Example 1

Floorplan around our laboratories and offices. Evaluated this environment with and without 'furniture' and for the cases where the antennas are omnidirectional or throwing two broad beams.

Empty environment	Environment with furniture
Signal strengths with omnidirectional antennas:
Signal strengths with two beam antennas:

Indoor Example 2

Domestic floorplan with walls, windows, doors and 'furniture'. High permittivity 'body' next to a transmitter moves through the environment.

Distributed Antenna System

Using several transmitter/receiver antennas within a wireless coverage area can be very effective in combatting the shadowing effects caused by solid buildings or traffic, as an unblocked path to one of the transmitter/receiver antennas is likely. Research program with Motorola is evaluating the signal propagation benefits and the extra complexity required in the backbone system needed to realise such systems.