High-speed Digital Link Research Articles

A space division multiplexed free-space-optical communication system that can auto-locate and fully self align with a remote transceiver

Free-Space Optical (FSO) systems offer the ability to distribute high speed digital links into remote and rural communities where terrain, installation cost or infrastructure security pose critical hurdles to deployment. A challenge in any point-to-point FSO system is initiating and maintaining optical alignment from the sender to the receiver. In this paper we propose and demonstrate a low-complexity self-aligning FSO prototype that can completely self-align with no requirement for initial manual positioning and could therefore form the opto-mechanical basis for a mesh network of optical transceivers. The prototype utilises off-the-shelf consumer electrical components and a bespoke alignment algorithm. We demonstrate an eight fibre spatially multiplexed link with a loss of 15 dB over 210 m.

A Novel Two-Port Behavioral Model for I/O Buffer Overclocking Simulation

This paper presents the first behavioral model solution to the computationally efficient simulation of digital I/O buffers under overclocking operation. Our physics-based two-port approach relies on predicting the timing signals that control the activation of the driver's output stage. The identified nonlinear dynamic model operators of the input port replace the concatenated fixed step-input describing functions of the previous table-based I/O buffer information specification and of other parametric approaches. The implemented gray-box model produces more accurate results than the previous methodologies when assessing the signal integrity performance of high-speed digital links in normal and overclocking conditions under various input excitations. However, it still preserves the computational efficiency recognized for its behavioral model predecessors.

Topological design of corporate communication networks

Recent construction of corporate communication networks with the use of high-speed digital links, etc., is becoming popular. Economical and reliable networks must be designed. Few papers have been published on the design of corporate communication networks. Moreover, some need improvement. This paper proposes a new topological design algorithm for efficiently constructing economical and reliable corporate communication networks. This algorithm achieves effective network design by utilizing the correct network information. The triangle network configuration, which provides higher reliability than two-connected networks with only a small additional cost, is proposed. Moreover, this paper proposes a new idea at a lower cost (cost lower bound) that evaluates the results obtained by various heuristic algorithms. Superiority of the proposed algorithm is verified by means of this cost lower bound.