WIND-FLEX - Indoor Wireless Telecommunications (IST-1999-10025)

The WIND-FLEX (Wireless Indoor Flexible High Bitrate Modem Architectures) project is one of the partners of the IST (Information Society Technologies) and part of the EU (European Union) 5th framework. 

The objective of the proposed research is to suggest a high bit-rate flexible and configurable modem architecture, which works in single-hop, ad hoc networks and provides a wireless access to the Internet in an indoor environment where slow mobility is required. The main emphasis will be in the OSI layers 1 and 2. The best possible performance with a reasonable complexity is attained by using a jointly optimized adaptive system which includes the multiple access method, diversity, modulation and coding, and equalization and decoding. The system is not optimized in advance but it will be adaptive and configurable in the run time. This is a step towards a software radio, which is presently too far in the future due to technological problems. Bit rates from 64 kbit/s up to 100 Mbit/s are considered at the frequency in the band of 17 GHz. 
DST has participated in the project by designining and implementing initially a static systolic FFT architecture for 128 complex points. Finally, DST has converted the FFT architecture into a reconfigurable architecture.

Regarding timing performance:
the operating frequency is (approx.) 120 Mhz. Considering that during the integration the architecture will use a different place and route circuit than that realized in the lab, there is a safety margin for integration purposes. In the design process NKUA uses schematic entry with the Quartus software for Altera FPGAs, with target device the APEX20KE600. Test compilation of the radix 2 block of the design shows that (on this particular chip) a total of 7% of its Logic Elements are used and a total of 4% of its Embedded System Blocks (essentially RAM) is used.

Paper Output