A Simulator For Differential Msk Direct Sequence Spread Spectrum

In this poster we shall present a simulator developed for complete simulation of a D-MSK DSSS (Differential Minimum Shift Keying Direct Sequence Spread Spectrum) system which operates in a multipath AWGN (Additive White Gaussian Noise) channel. The simulator is "complete" in the sense that it simulates the transmitter, the channel, and the receiver. This includes precise simulation of the various synchronization loops in the receiver, ability to simulate a virtually unlimited number of multipath interferers with arbitrary amplitudes, and complete control over the parameters of the communications link. The simulator is operated through a Matlab GUI (Graphical User Interface) which runs proprietary code written in Matlab. In addition to discussing the simulator itself, we shall also outline one of the unique applications of the simulation program, which is in the development of a novel technique for acoustic travel-time measurement in geophysical exploration

Mitigating Interference between IEEE 802.16

A rudimentary approach to mitigate interference issues in license-exempt 802.16 systems is presented. This approach operates by permitting each Base Station (BS), and associated Subscriber Stations (SSs) to remain inactive for a specified fraction of the time. Other systems can then transmit with a reduced likelihood of interference. A simulator was developed to determine how this system performs. The results show that the throughput of the system is very sensitive to the fraction of time each BS is active; the system throughput is maximised when each BS is active less than 40% of the time for the scenarios studied. The results demonstrate a discrepancy between uplink and downlink throughput which can be attributed to the greater amount of overheads in the uplink. Finally, the results show that broadcast information being transmitted periodically at full power has a significant detrimental impact on the system