Another baseband processor option for CDMA is LSI Logic's new CBP-3.0, targeted at IS-95A/B designs. It contains an ARM7 controller, two OAKDSPCore processors, mixed-signal circuitry, and standard-cell logic to provide a complete, low-power baseband solution.
While a DSP dominates, some manufacturers are still opting for an ASIC or logic solution to baseband processing in basestation design where size and power consumption are less of an issue. In complex CDMA receivers or those that must translate multiple protocols, an ASIC or FPGA is the only thing fast enough to do the job. For example, PLD manufacturer Altera has chip sets for WCDMA designs.
Some additional technologies to be aware of and factor into your 3G plans are speech recognition, voice response, smart antennas, and Bluetooth. Speech recognition seems to be a natural technology to include in any phone. Why not use it for control purposes too? This isn't new. It has already been tried with cell phones, and a few products are now available. But users report unreliable translation.
A number of companies are working on next-generation systems and services. Some that you should pay attention to include SpeechWorks International Inc., Nuance Communications Inc., Talk2 Technology Inc., phone.com and software.com (they recently merged), and Vocal Point Technologies. The real breakthrough may result from VoiceXML, a voice XTML that's de-signed for writing voice-accessible Internet content.
Another development is text-to-voice software that takes e-mails or messages and converts them to voice, a feature that will help the cell-phone distraction problem.
Smart antennas are basestation arrays that employ military-style phased arrays with DSP computing power to automatically adapt and reconfigure their radiation patterns to fit the traffic. By becoming more directional and by being able to control beam width as well as azimuth on both the uplink and downlink, these antennas permit carriers to increase their capacity without adding new equipment, simply be-cause carriers can implement a more efficient frequency reuse plan.
While not specifically a 3G technology, many carriers are expected to employ adaptive antennas in their systems at about the time they implement 3G. As the cost of new cell sites skyrockets, smart antennas seem to be a smart choice for increasing the capacity of minimal additional expenses. Furthermore, it might figure into a location-detection scheme. Some companies working on smart antennas are AirNet Communications Corp., Ericsson, and Metawave Communications Corp.
Bluetooth Headsets Available
Bluetooth is the standard for low-power radio transceivers that can be built into other electronic products to make them wireless. Designed as a wireless cable replacement, low-cost Bluetooth ICs make it possible for virtually any electronic device to communicate with any other device over a short distance. Bluetooth operates in the 2.4-GHz unlicensed ISM band up to a distance of about 10 meters. Bluetooth's founder, Ericsson, is currently making Bluetooth-enabled headsets for cell phones and cordless phones.
Cost and interference problems are the biggest issues when incorporating Bluetooth in a handset. These will certainly arise when two complete wireless transceivers, including antennas, are packaged in the same small housing.
Most crystal-ball gazers see 4G systems with data rates of up to 20 Mbits/s. Some also think that a few of the 3G applications, like video, may not be implemented until 4G comes around. Perhaps even voice communications will be packetized via the VoIP standard.
Furthermore, we can probably look for an even newer air interface. Orthogonal frequency division mulitplexing (OFDM) keeps coming up as a possibility. This super-complex method is now practical thanks to inexpensive DSPs. Plus, it's far more robust in terms of weak-signal and multipath reception. But who knows? Maybe the enigmatic ultra-wide-bandwidth (UWB) pulse technology will mature and come forward to reveal some true benefits.