DAC 2012: Connecting Emulation to the Real World of Wireless Interfaces

This is certainly the most connected DAC I have been to so far. Tweets and connections everywhere, blogging is happening left and right. A lot of the attendees hold their wireless devices in their hands. It is rewarding that we are part of enabling all that. Living proof of that came today from our System Development Suite partner Rohde & Schwartz. Andreas Roessler, Technology Manager  for R&S America, presented at the EDA360 Theatre on "LTE Advanced - Taking LTE to True 4G".

Andreas started off by showing the path to Long Term Evolution (LTE) and its release 8. Lots of technologies led to the next generation wireless standards, including dual layer beamforming, eMBMS enhancements, DL MIMO 8x8, UL MIMO 2x2, enhanced SC-FDMA and public warning systems, just to mention a few. He compared LTE with LTE Advanced - Release 10 - and its completion status. For LTE advanced carrier aggregation is the most important priority feature.

There are a high number of specific band combinations now worked on in 3GPP, LTE Advanced is not only aimed at increasing the peak data rate, but mainly adding flexibility in spectrum use and resource allocation. Bottom line is that the implementation efforts are significant. Andreas proceeded to explain carrier aggregation in more detail - two or more component carriers are aggregated in LTE-Advanced in order to support wider bandwidths up to 100 MHz. Andreas also provided a comparison of cross-carrier scheduling schemes and the enhanced uplink feedback mechanisms, leaving the audience with a good impression of the complexity design teams supporting LTE advanced have to deal with.

So how do Rohde & Schwartz and Cadence relate? All this complexity of advanced wireless protocols needs to be tested. In order to meet time to market demands, tests need to happen as early as possible in the design flow and while the design is under development. Just writing smart test benches to verifiy designer's RTL is not enough - real world stimulus needs to be applied. In order to achieve that, the signal generators providing downlink signal generation and the signal analyzers providing LTE Advanced uplink analysis can be connected to our Palladium XP Verification Computing Platform as indicated in the following picture.

The key to the connection is a digital signal interface module which provides the IQ signaling between the Palladium XP hardware and the signal generator/analyzer combination. With designs in Palladium XP running at up to 4MHz, real test data is down sampled and applied to the design, allowing tests with real world stimulus. Without these capabilities, design teams would risk not hitting all corner cases which are provided using the signal generation with the Rohde & Schwarz equipment.

Even though I don't quite know which standard my phone actually connects to at any given time, let me tweet about this right away, and it is great to know that our technology helped validate that these tasks I have gotten so used to as part of normal life actually can work!

Frank Schirrmeister