Prototyping a MIMO W-CDMA system using a system-level approach Louis Bélanger Sébastien Roy Taofik Saïdi Business and Product Development Manager Assistant Professor PhD candidate LYRtech Signal Processing Dept. of Electrical and Comp. Eng. Dept. of Electrical and Comp. Eng. 4494, boul. Wilfrid-Hamel, suite 100 Université Laval Université Laval Québec (Québec) Québec (Québec) Québec (Québec) G1P 2J7 Canada G1K 7P4 Canada G1K 7P4 Canada T: 1-418-877-4644 T: 1-418-656-2131, ext. 2981 louis.belanger@lyrtech.com S.Roy@ieee.org saidi@gel.ulaval.ca Olivier Sentieys Professeur des unversités École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT) BP 447, 6 rue du Kérampont 22305 Lannion, France sentieys@enssat.fr T: +33 (0)2 96 46 66 41 Abstract— This paper describes the development and proto- typing of a MIMO (Multiple-Input Multiple Output) wireless link designed to operate under the WCDMA third generation cellular standard. The said development is performed in an integrated, system-level fashion on a DSP/FPGA development platform, the Lyrtech SignalMaster.The first part of the paper will succintly describe the evolution and the main features of the WCDMA standard. Likewise, the second part reviews the basic concepts of space-time processing and MIMO communications. The third part details the system-level design flow and prototyp- ing approach exploiting the strong linkage between Simulink and the SignalMaster platform. Finally, preliminary implementation results and comparisons with other design and prototyping tools and approaches are provided. I. I NTRODUCTION Wireless cellular telephony nowadays is characterized by a multitude of standards including the still-in-use venerable first-generation AMPS (analog cellular in the 800 MHz range) standard, the globally successful second-generation (2G) GSM standard (operating in 3 different bands in different regions of the globe: 900, 1800 and 1900 MHz), other 2G standards such as IS-95, IS-136, PDC, and emerging third generation (3G) standards such as EDGE (Enhanced Data rates for GSM Evo- lution), WCDMA (Wideband Code-Division Multiple Access) and cdma2000. The evolution of wireless cellular is naturally evolving towards broadband wireless access characterized by high data rates, a multiservice, packet-based infrastructure (thus break- ing free from the classical switch-based telephone paradigm). 3G systems (and most notably WCDMA) should in principle offer full-duplex 2 Mbps data rates. As they are slowly being deployed, however, it seems that maximum effective rates are in fact 384 kbps downstream and 64 kbps upstream. This suggests that true broadband access in the current cellular evolution path will have to wait for the advent of 4G. Wireless LAN technology, however, has been a huge com- mercial success under the auspices of the 802.11a/b/g (WiFi) standards which present the advantage of low-cost availability of both service and hardware almost anywhere on Earth. The so-called WiFi technology readily offers nominal data rates of 11 and 54 Mbps (although in practice, throughput is typically limited to approximately 32 Mbps). Is WiFi the broadband access system of the future? Not quite, despite the huge interest it generates in cellular service providers. Indeed, while it does offer the high data rates, 802.11 as it stands today offers very limited support for mobility, both in terms of roaming support (handover) and dealing with hostile Doppler effects generated by high-speed mobility. It is well-known that the relatively low data rates in cellular are mainly due to Doppler-induced fast variations in the channels. Furthermore, 802.11 has a very limited range because of the transmit power limitations imposed in the unlicensed bands it exploits. Finally, operation in unlicensed bands does entail unknown interference conditions as well as increased spectrum crowding due to WiFi’s own success. However, the continuing evolution of 802.11 and similar technologies suggests a convergence with cellular, as range is increased and higher levels of support for mobility are incorporated. This multitude of coexisting standards and the attractiveness