CDMA Chip Suppliers Inch Closer to Total Solution
SATURDAY, MARCH 25, 2000 12:13 AM - CMP Media
Mar. 24, 2000 (Electronic Buyers News - CMP via COMTEX) -- The barriers to entry continue to disappear for OEMs building handsets for CDMA applications. As leading IC suppliers move to a new generation of silicon, they're embedding a wider mix of functions on-chip, enabling new applications with enhanced DSP capabilities, and forging new partnerships with leading RF IC developers and design houses to simplify the handset-development process.
What is involved is giving OEMs a full speaker/microphone-to-antenna solution, according to Luis Pineda, vice president of product management for CDMA technologies at Qualcomm Inc. in San Diego.
Up for grabs is a market with undeniably huge potential, particularly in emerging segments.
Last year, for example, China Unicom, a competitor to the state-run China Telecom, announced plans for a CDMA network by 2003 with a capacity of 50 million lines and more than 30 million users.
With similar efforts under way in various countries, it's clear why analysts at Morgan Stanley Dean Witter & Co. say that worldwide shipments of IS-95 CDMA handsets will jump from 48 million units in 1999 to more than 265 million in 2003.
And handsets represent just part of the CDMA market. Companies like AirPrime Inc. are using CDMA baseband processors from LSI Logic Corp. to build modem cards that will provide Internet access for a wide variety of handheld devices.
Those enticing prospects are not only driving development efforts by market leader Qualcomm, which originally developed the technology for military applications, and its licensees LSI Logic, PrairieComm Inc., and DSP Communications Inc., which was recently acquired by Intel. It is also drawing new players into the market.
Both Samsung Electronics Co. Ltd. and Hitachi Semiconductor (America) Inc. recently announced intentions to develop CDMA chips. And Philips Semiconductors is reportedly negotiating with Qualcomm to renew a CDMA license previously owned by VLSI Technology Inc. before it was acquired by the Netherlands-based semiconductor giant.
Analog focus
In the last year, leading CDMA silicon suppliers moved from shipping pure digital CMOS devices to integrating many of the required analog baseband functions on-chip. Last September, Qualcomm began shipping samples of its MSM3100, the company's first CDMA offering to incorporate analog cores using mixed-signal CMOS.
"What we did was to bring on-chip functions that used to require external chips such as the voice codec, PLL, and D/A and A/D converters, " Pineda said.
Licensees of Qualcomm's CDMA technology are following a similar strategy. "We've been investing heavily in mixed-signal IP development," said Greg Helton, director of marketing for the Wireless Products Division at LSI Logic, Milpitas, Calif.
At the same time, CDMA IC designers are beefing up the processing capabilities of their baseband chips. The emergence of a growing number of real-time voice, data, and video applications is placing new demands on handset computational requirements.
LSI Logic reportedly will debut a new CDMA baseband processor later this year.
The company's current CDMA baseband processor solution integrates an ARM7TDMI-based CPU with two OAKDSPCore DSPs to support the growing array of data, voice, and multimedia applications migrating onto current-generation handsets.
"The mips requirements on the modem functions are pretty significant today, so designing the software becomes a real issue," Helton said. "Instead of trying to force incompatible pieces into a marriage, it's much better to let the real-time operations be taken care of by one DSP, and applications and voice-oriented algorithms be taken care of by a second DSP."
The addition of more DSP capability has opened up tremendous opportunities to integrate new applications. Last month, Qualcomm introduced the MSM3300, the company's first multimedia-enabled CDMA solution, which is based on its MSM3100 chipset architecture.
With its enhanced DSP functions, the new chipset and supporting software add GPS location capability, an embedded Bluetooth baseband processor, and support for entertainment applications such as Qtunes MP3 player software and Compact Media Extension MIDI-based multimedia software.
"An OEM previously needed an external DSP to perform these applications," Pineda noted.
But if the processing demands of next-generation wireless platforms continue to escalate, IC developers may have to find more efficient ways to interconnect and schedule tasks in systems using multiple DSPs.
Engineers at Lucent Technologies Inc.'s Bell Labs recently launched an effort in this arena. The company announced the development of a new approach to building high-performance signal-processing platforms that use a high-speed, cache-coherent, split-translation bus or interconnect fabric to allow multiple DSP cores to share communication and memory resources on a single chip.
Called Daytona, this engine promises to overcome many of the challenges designers have faced writing software for multi-DSP chips made with custom components. A tool box developed for the technology allows designers to string together components to build a variety of multi-DSP designs.
Lucent's first prototype of the technology, disclosed in February at the International Solid State Circuits Conference in San Francisco, linked four 100-MHz DSPs with a controller that manages the flow of data between each DSP, a shared memory, and an I/O controller that controls on- and off-chip data flow.
By sharing communications and memory resources, designers can treat the system as a single processor and simplify program development. The cache-coherent bus ensures that designs will conform to known latency limits and meet the needs of real-time tasks. The shared memory model also reduces cost and power requirements.
"Many of the ICs that mount multiple DSPs on a single chip have been put together for a specific application, and the way in which the components share memory and handle I/O are constructed on an ad hoc basis for that particular application," said Bryan Ackland, head of the DSP and VLSI systems research department at Bell Labs, Berkeley Heights, N.J.
"So what you're doing is sort of creating a from-the-ground-up architecture design every time you design a new chip. What we're trying to do is [create] a framework for hooking DSPs together in which, although you may change the individual components, the underlying framework stays the same and the software framework behind it also stays approximately the same. That allows you to get a lot more reusability out of the system-level architecture," Ackland said.
RF dilemma
There's little doubt the toughest challenge for CDMA IC suppliers from an integration standpoint lies on the RF side. While some vendors have predicted the eventual implementation of RF functions into CMOS, solutions are still a number of years away.
"When you look at the expertise that goes into RF vs. baseband technology, there's so little synergy between the two," LSI Logic's Helton said.
To round out their portfolios and offer a more complete solution to OEMs, some CDMA IC suppliers have begun to forge partnerships with leading RFIC makers.
In February, Qualcomm announced a deal with Greensboro, N.C.-based RF Micro Devices Inc., the largest supplier of gallium arsenide, heterojunction-bipolar-transistor RFICs, to provide power amplifiers for CDMA-handset applications.
The alliance's first product, the PA3100 PA module, along with Qualcomm's existing RFT3100 transmit chip, comprise the entire radio portion of the transmit chain for IS-95B-compliant handsets.
Qualcomm is packaging as a single CDMA solution the power amp with the MSM3100 Mobile Station Modem baseband processing chip, the RFT3100/RFR3100 receive chip, and the PM1000 power-management chip.
The PA3100 series will initially be available in three versions: the PA3100-2 for the 824/849-MHz cellular band, the PA3100-3 for the 1,850/1,910-MHz PCS band, and the PA3100-3K for the 1,750/1,780-MHz PCS band.
Designed to support handsets using a single-cell lithium-ion battery, the PCS PA3100 module in CDMA mode delivers 28-dBm linear-output power with 25-dB linear gain and 33% linear efficiency. The cellular module provides 28-dBm linear-output power with 34% efficiency in CDMA mode and 31.5 dBm with 50% efficiency in AMPS mode. Samples will ship in the second quarter, with production slated for the third quarter.
Meeting requirements While component integration presents one set of challenges, developing a manufacturable handset design compliant with industry regulations requires an entirely different set of skills.
Some semiconductor makers are attempting to simplify the process and take the next step for OEMs by forging alliances with wireless-design service companies. The idea is that by providing printed-circuit-board and software-customization services, these companies can reduce the risk to the OEM and shorten time-to-market.
A case in point is LSI Logic's recent agreement with RTX Telecom A/S, a Denmark-based supplier of turnkey design services for wireless-communications systems. Using LSI Logic's single-chip CDMA baseband processor, RTX Telecom will develop IS-95-compliant turnkey solutions and offer contract services for CDG-type approval. The design will be based on widely available RF components.
"Normally, it takes a year from concept to production in handset design," Helton said. "This relationship will give our customers the benefit of a drastically reduced design cycle."
In the meantime, OEMs are continuing to search for ways to drive down handset footprint, cost, and power consumption simultaneously. One area ripe for improvement is passives integration. Passive devices now take up as much as 80% of a cell phone's board space and in some cases represent more than 90% of the product's device count.
This issue promises significant payoff in RF-device integration, particularly as the market moves toward handsets capable of supporting multiple bands and multiple modes and designers pack more functionality into a smaller space.
Nokia has said that in the RF section of its 1998 handset designs, passives represented 90% of the components, took up 85% of the space, and accounted for 70% of the cost. In Motorola Inc.'s iDEN i1000 phone manufactured last year, the RF/IF section occupied 23% of the handset area and constituted 62% of the system's components.
"It's been difficult to integrate passives without the performance of the devices ending up quite different from what they were when they were discretes," said Deepak Kulkarni, business manager of IPDs at Intarsia Corp., Fremont, Calif.
The company uses thin-film technology, chip-scale packaging, and large-panel manufacturing to integrate passives for use in wireless RF and portable products. Intarsia offers characterized models and libraries of its components that allow OEMs to define RF thin-film solutions in extremely small form factors. "We can reduce size by as much as 50%," Kulkarni said.
Move to 3G
At the same time, CDMA IC suppliers are already preparing next-generation (3G) silicon solutions for a handset market that Forward Concepts Co., Tempe, Ariz., projects will grow from $1.5 billion in 2001 to $9.2 billion in 2005.
Earlier this year, Qualcomm brought to market the first samples and system software for its MSM5000 Mobile Station Modem. As the first CDMA 1x Multi-Carrier solution compliant with the 3G standard specified by the International Telecommunications Union (ITU), the new chipset will allow manufacturers to begin designing next-generation products and offer longer standby times and higher data-rate capabilities.
To make the migration as painless as possible, Qualcomm engineers have designed the MSM5000 to be pin-compatible with its earlier MSM3000 chipset and architecture. The new chipset supports data rates of 153.6 Kbits/s on both forward and reverse links, significantly faster than the ITU's requirement of 144 Kbits/s.
Features such as 800-Hz forward power control and new modulation and coding schemes help give operators up to twice the overall capacity of IS-95A and IS-95B systems. The addition of a new technology called Quick Paging Channel helps extend standby time, according to the company.
With standards still in flux and the market fragmented, many IC suppliers have hedged their bets by developing multiple solutions. Before it was acquired by Intel, for example, DSP Communications introduced separate chipsets for W-CDMA and more recently for cdma2000.
The cdma2000 offering, called the D6011, meets Telecommunications Industry Association requirements for phase one of the standard and offers data rates up to 153 Kbits/s for up and down links. The baseband processor features an ARM7TDMI core, a TeakDSP core, and a range of peripheral functions, including USB, UARTs, and timers. Many analysts, however, expect Intel to integrate a new DSP that it is co-developing with Analog Devices Inc. into DSPC's CDMA technology.
PrairieComm, Rolling Meadows, Ill., is also prepping a 3G solution, but is eyeing dual-mode CDMA/GSM baseband designs. The company announced in February a digital baseband IC that will comply with the 1X specification for cdma2000 as well as GSM standards. By supporting both CDMA and GSM, the baseband processor will enable handset OEMs to build a single phone that works worldwide, company executives said.
To help designers simulate their designs while 3G standards continue to evolve, Sirius Communications NV, the Leuven, Belgium-based start-up that last year announced a reconfigurable baseband core for W-CDMA, has recently added a C-language model of the core.
The CDMAx core is available for licensing and supports the Japanese and European versions of W-CDMA, but doesn't support the U.S. version, cdma2000. Sirius executives say CDMAx, along with the new C-language model, will give developers a shortcut to the 3G handset market.
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