Commack, NY -- The ethereal concept of cognitive radio will be seeking paths to corporeal form among the many wireless breakthroughs being presented at ISSCC 2010 conference that starts on Sunday in San Francisco. From highly integrated SAW-less front ends to multistandard, multiband systems on chip to emerging 60-GHz interfaces, the foundational elements of our ubiquitous wireless future will be on display for all to see.
Defined by Joseph Mitola, the original coiner of the term as, "a really smart radio that would be self-aware, RF-aware, user-aware, and that would include language technology and machine vision along with a lot of high-fidelity knowledge of the radio environment," cognitive radio has become a catch-all bucket for all sorts of radio intelligence. Got transmit power control? Definitely CR. Have adaptive frequency hopping? You're in! Can your radio operate in more than one band? You're a CR pioneer!
While all these 'features' are elements of what Mitola had in mind, the true vision goes way beyond these singular advancements into truly 'intelligent' radios that can operate in and avoid interference in any band based on a priori knowledge to predict what bands are open, where interference may come from and what the user's application may be. Much of the intelligence for this will reside at a higher level in software, but the capability to act upon and take advantage of that intelligence depends on advancing the state of the art in radio design. That's where ISSCC comes in.
At the conference, a veritable flotilla of research will bubble to the surface, particularly in the area of multimode, multiband radio design. Broadcom and Qualcomm will team up to show how they relied upon the sharing of common blocks to realize an SoC for Bluetooth, FM and wireless LAN (WLAN) radios with an integrated power amplifier and a sensitivity of down to -91 dBm. IMEC researchers will show off their 0.1-to-3-GHz multistandard 40-nm CMOS transceiver.
Analog Devices will be going head to head with Samsung in mobile TV when it describes a 65-nm CMOS multistandard, multiband mobile broadcasting receiver SoC (paper 25.6) that covers DAB/T-DMB, ISDB-T 1seg and FM. The receiver consumes 35mW and features sensitivities of -103dBm, -98dBm, and 1dBuV for T-DMB, 1seg and FM, respectively. In paper 25.7, Samsung will unveil its SoC, also in 65-nm CMOS. How the two compare will be interesting to find out.
Getting the SAWs out
As the integration of radios has advanced through the process nodes, the amount of space and cost taken up by passive components such as SAW filters has increased to the point that they are now proportionally a major factor in the BOM and layout. Reducing their size, or getting rid of many altogether, would clear a hurdle to more fully integrated, multimode transceivers. This issue has come through the fore at this year's ISSCC, not only via a special tutorial session on Sunday, hosted by Dr. Hooman Darabi, but throughout the conference in paper after paper dealing with, in particular, the subject of zero-IF or direct-conversion radios.
By eliminating the intermediate-frequency (IF) stage, these radios no longer need a SAW filter at that point and so lower cost and space requirements. However, the penalty is increased risk of interference such as local-oscillator feedthrough.
Researchers from Toshiba will show how they got around this problem in paper 25.4 where they will describe a direct-conversion Mobile WiMAX SoC in 65-nm CMOS with inductorless local-oscillator distribution.
In the cellular track, researchers from Texas Instruments and Delft University (The Netherlands) will show a SAW-less all-digital polar EDGE transmitter, while researchers from Advanced Circuit Pursuit (Zurich, Switzerland) will present in paper 3.3 a tri-band SAW-less WCDMA/HSPA RF CMOS transceiver with on-chip dc/dc converter connectable to a battery.
60-GHz heating up
As the battle for wireless video distribution wages on, 60 GHz continue to gain traction against the various incumbents, particularly WLANs. ISSCC will add to the fray. In Session 2, expect to see two papers focused on advancing the state of the art here. A favorite among IMEC researchers, they will present a wideband beamformer for a phased-array 60-GHz receiver in 40-nm digital CMOS. Researchers from Delft will show a 60-GHz-band 2x2 phased-array transmitter in 65-nm CMOS.
See you at the conference. I'll be tweeting from there @Patrick_Mannion.