Electronic Design

Power Issues May Hamper The Portable's "Smart" Future

Back when I was an executive of two major technology corporations, I was always fascinated by the strategic planning process. That's where we attempted to predict which future technologies would make an impact on us and what our new products would be two, five, and 10 years out.

In the two-year timeframe, our predictions were pretty good—most big trends are relatively easy to spot. The tough part was reacting fast enough to get a piece of the action before the competition exploded. Five years out, the predictions became less accurate but useful. And at 10 years, we were telling fairy tales and just making up stuff.

But the exercise forced us to think and really push our limits. That's where the really novel ideas originate. Just go back 10 years and compare that to the present in any electronic specialty. Most of today's products were unpredictable. Did anybody foresee MP3 players and music downloading, BlackBerry e-mail devices, affordable digital camera phones, satellite radio, and a multimillion-dollar ring-tone business? And don't forget, most of our corporate incomes amazingly come from the newest products. So we need to know what's coming.

SOME PREDICTIONS
First, the cell phone will—and maybe already has—become the center of our electronic universe. TV and the emergence of the PC dominated the 20th century. Today and even more so for the future, the focus is on communications and consumer electronics. Already, the cell phone is our constant companion. It has evolved into an indispensable device that provides us with entertainment like TV and audio in addition to location-based services and e-mail, short messaging, and Internet access (Fig. 1).

Next, the software-defined radio (SDR) will become the architecture of choice for most wireless devices. SDR is already being increasingly adopted in cell-phone handsets, basestations, and two-way radios (see www.sdrforum.com for details). As analog-to-digital converters (ADCs) accelerate, we can digitize the signal earlier in the signal chain, then do all filtering, conversion, modulation, demodulation, and other functions in DSP. Commercial analog-to-digital converters (ADCs) can sample at rates to 400 Mbits/s, with higher rates on the way. But an analog downconverter is needed up front.

A New York company, Hypres, came up with a cryogenically cooled ADC and DSP to create the proverbial All Digital radio that works well into the gigahertz range (www.hypres.com). So we're getting close to that ideal SDR in which the antenna jack is the input to the ADC (Fig. 2). SDR is already finding use in the military's Joint Tactical Radio System (JTRS), and more recently in cell-phone basestations.

In addition, cognitive radio will combine with SDR to make adaptable universal smart radios. Cognitive radio is any radio that can sense its environment, such as radio spectrum and nearby signal sources. It then learns the landscape and automatically adapts to the situation. This may mean not only a frequency shift, but also a complete change in the air interface and wireless protocol. Thanks to the FCC's recent approval, future cognitive radios will conserve and reuse spectrum space. They also will be able to download new configurations when needed. JTRS military radios will be the first to experience the benefits of these cognitive traits, but they will come into use in civilian government/public service radios next, with applications in cell phones afterward.

And then, believe it or not, 4G could appear before 3G. Simply put, 3G is floundering. Even with SDR and cognitive radio both making 3G easier, 3G will continue to get pushed back. This is especially true in the U.S., where carriers seem content with the faster versions of cdma2000 and GSM/GPRS/EDGE. The high cost of new infrastructure and lack of volume in handsets are other factors. Although HSDPA will give UTMS/3GPP WCDMA 3G a boost, an OFDM 4G standard may be the next big leap. Then again, with the potential for VoIP-based Wi-Fi and WiMAX handsets, does 4G even have a chance?

Antennas will continue to get smarter, too. We're already seeing this in the multiple-input/multiple-output (MIMO) and beam-forming antennas for cell-phone systems and wireless local-area networks (WLANs). Further advances will make space-division multiple access even more practical. But because antennas are resonant by nature, antenna manufacturers will need to find ways to create broader-band antennas that are also directional. The ultra-wideband (UWB) developers know something about this, and no doubt the antenna community will respond with innovative designs as well as automatic on-chip tuning/matching circuits to make SDR and cognitive radio practical.

Look for location-based services to emerge. Now that cell phones have their mandated E911 and location capability, carriers will begin to test and add a variety of location-based services. Location will be critical to most future applications, but those applications have yet to mature.

Meanwhile, video will become the next popular cell-phone feature. It's appearing in limited form today. But improving multimedia handset architectures and innovative services from the carriers will soon have us watching TV on our phones in airport waiting areas, the beach, and everywhere else—but hopefully not in the car. Larger color screens and more multimedia options will be common as well.

SOME FAILURES, TOO
On the flip side, speech recognition won't be successful—again. The technology has improved, but it's not good enough for the general public. There's no doubt it would be practical in a cell phone, yet it's still too primitive and complex for the average user. Enhancement attempts will continue nonetheless.

Orthogonal frequency-division multiplexing (OFDM) will be everywhere. We all thought spread spectrum was "the" final frontier. Then, along came the competing broadband wireless technology, and whamo! Thanks to improved and low-cost DSP, OFDM is showing up in every wireless product except for cell phones. There's no doubt that any 4G system will use it, though.

How about wireless ubiquity? Cell-phone growth will march on. Even the replacement market will thrive with new features like MP3 players, TV, location services, and the seamless worldwide roaming made possible by a cognitive SDR.

Furthermore, wireless will reach out to more applications beyond the local-area network (LAN). LANs will continue to gain speed (100 to 250 Mbits/s) with the latest iteration of the IEEE standard, 802.11n. Wireless broadband like WiMAX will carve itself out a good niche in the broadband services and back-haul business. WiMAX (802.16e) also will end up as a good longer-range mobile service, because the IEEE 802.20 mobile standard seems dead in the water at this point.

Short-range industrial/scientific/medical (ISM) and Bluetooth radios will continue to proliferate. ZigBee will make practical inexpensive remote monitoring and control. It also will makee wireless mesh sensor networks a reality. Wireless will come to the home with UWB or 802.11n to interconnect TVs, DVRs, DVDs, large-screen HDTVs, and other devices.

Laptops will forge ahead, and PDAs will fade away. Laptops actually sell better than desktops today. Look for that trend to continue with added wireless capability—not only Wi-Fi but also WiMAX and even advanced cell-phone technology, probably 4G rather than 3G. Some cell phones like the Black-Berry and Palm Handspring Treo already have absorbed PDA functionality.

Battery technology won't keep pace with the onslaught of technologies, though. Battery power controls the mobile/portable field. As more and more goodies populate our portable devices, the greater the power consumption and the shorter the operating time. The problem is being addressed from several directions.

Chip companies are decreasing the power consumption of handset chips and coming up with better power-management chips and schemes. Some better batteries, such as the lithiums, have arrived. But if the trend continues toward more high-power accessories like video on larger color screens and hard drives—not to mention the drain of the DSP in SDR and cognitive radios—we'll hit the wall sooner or later. Electrochemistry can only take batteries so far. The latest iteration of lithium cells is great, but nothing promising lies beyond that.

One answer may come in the form of fuel cells. These elusive items have rooted around for decades. Despite some forward development, they're still too large, costly, and otherwise primitive for most portable devices. The new smaller methanol recharged fuel cells hold out promise. Unfortunately, they're still large, and their value is more in recharging the batteries than in replacing them. Continued development will help, but don't look for any big breakthroughs anytime soon.

Get ready to trade off battery operation time for glitzy accessories. What we need is a big dose of what Dupont used to brag about: "Better living through chemistry."

21ST CENTURY RADIO
Look for growth in digital broadcast radios. Satellite radio from Sirius and XM have been around for a while, and the number of subscribers is still increasing. More satellite digital radios are being installed in cars, and fully portable models for use at the beach are available. Subscriber satellite radio is all about choice. With over 100 channels of music, sports, news, and talk on both services, there is something for everyone.

HD (high-definition) radio is on the air as well. Even less known than satellite radio, this new version of standard AM and FM radio is now available in most states. There are 768 licensed stations, and just about half of them are on the air. These new systems use compression and digital modulation to squeeze CD-quality audio into the existing AM and FM channels.

Aftermarket car radios are available too. Auto makers will eventually get around to offering HD radios. Hopefully, portable units will follow. Here's to the higher quality, less noise and fading, and data services these new radio choices offer! Wake up, you guys, this stuff is here now!

One last point: It always takes more time to adopt new technology than we think. In fact, the technology to create most of the aforementioned items is available now. The major factors affecting development and adoption are economic, cultural, social, regulatory, and standards-driven. Add two to three years to the time of the peak hype, and you'll be much closer to the time of realization.

TAGS: Digital ICs
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