Acreo Uses Visual System Simulator to Successfully Optimize System Performance of Complex UWB Transceiver


Design Challenge 

The need for higher capacities within Internet infrastructure is driving the demand for network architectures capable of supporting 100Gb/s Ethernet (IP) based traffic. One such bandwidth-efficient technology being explored is sub-carrier multiplexing (SCM), where quadrature modulated (QAM) signals on different carrier frequencies are combined and subsequently encoded onto an optical carrier. This transceiver approach capitalizes on the increasing speed of silicon technology (65nm complementary metal oxide semiconductor CMOS process on HR-SOI substrate) to perform more of the signal processing in the electrical domain before converting to light.

Solution: What design problem did AWR's software help you to solve?

We needed to create a SCM transceiver link suitable for 100Gb/s transmission. The system-level development of a SCM transceiver link was modeled within AWR's Visual System Simulator. This RF system model enabled us to assess the influence of component performance in the electrical domain, particularly non-linearity and noise, with respect to the SCM link performance requirements. The design of critical component building blocks in the 65nm CMOS SOI process such as IQ modulators, power combiners, and low noise amplifiers (LNAs) for the SCM transceiver, were done at the circuit level. The performance of these components was then assessed in the VSS system simulation environment to investigate the capabilities of CMOS for next generation optical networking with the SCM architecture.

"Using Visual System Simulator together with Matlab® to create the RF system model proved to be a straightforward task." said Lars Pettersson, research engineer at Acreo. "The flexibility, ease-of-use, and open platform of Visual System Simulator was a very positive feature. Visual System Simulator gave a good understanding of how group delay variations affected the whole system performance and we were able to optimize the system using this knowledge."