In order to adapt to the the requirement of the Instruction Set Simulator (ISS) simulation speed in embedded system development, an improved ISS technology was put forward.The technology introduced instruction preprocessing, dynamic decode cache structure, multi-thread C function generation and dynamic scheduling technique based on the existing static multi-core simulator to achieve the optimization of the simulator performance. This technique has been applied successfully in forming OPT-ISS, which is based on IME-Diamond multi-core DSP processor. The experimental results show that this technique improves the simulation speed indeed.

In order to reduce the outage probability and enhance the stability of cognitive system, an improved algorithm of spectrum allocation based on classical graph coloring model was proposed. A difference factor of spectrum's idle time and user's request time was introduced. For every cognitive user, the algorithm allocated spectrums according to two factors: the spectrum efficiency and the time difference factor. Cognitive user with greater product value of the two factors was prior. The simulation results show that the outage probability of improved algorithm is far below that of the previous algorithm.