PicoChip Introduces Low-Power Femtocell Chip, Reference Design
September 20, 2010—A friend of mine—Brian Fuller, formerly with Low-Power Design—recently moved from his suburban home back to the urban canyons of San Francisco. Complaining that the only way he could receive a cellular call at home was to stand by the window, he went out and bought a femtocell, which gave him “five-bar reception” throughout the house.
Brian isn’t the only femtocell convert—carriers are, too. The dramatic rise in cellular data traffic—aggravated in no small part by the popularity of Apple’s iPhone—has started an expensive race to build out networks. It’s a lot cheaper to put up picocells (range to 200 meters) and femtocells (range 10 meters), which then use wireline backhaul, than to put up a lot of expensive basestations.
Picochip this month announced its the PC333, the first chip specifically designed to extend the femtocell into the realm of public access infrastructure such as metro femto, rural femto and strand-mounted systems. The PC333 System-on-Chip (SoC) device is the first femtocell chip to support 32 channels (scalable to 64) for simultaneous voice and HSPA+ data, the first to support MIMO, the first to support soft-handover and the first to conform to the Local Area Basestation (LABS) standard.
Rupert Baines, VP Marketing at picoChip, explained to Low-Power Wireless that by providing strong, local service to handsets, femtocells reduce the need for handsets to “shout” at the basestation, which means they run at reduced RF levels, which in turn results in longer battery life. Voice quality is also better, since the basestation doesn’t need to scale back on the data rate as it will do under weak signal conditions. Citing a study be Telefonica, Baines asserted that “Femtocells provide 10-20 times higher bps/Hz/area than conventional macrocell,” enabling data rates that are on average 8x faster than you can expect from a standard basestation.
The PC333 runs on a 700MHz ARM chip with TrustZone and variety of specialized hardware features for security. As well as LABS conformance and release 8 HSPA+ (42Mbps downlink, 11 Mpbps uplink), the PC333 supports soft handover, receive diversity, and MIMO or dual-carrier. It samples to lead customers in 4Q2010.
That’s the infrastructure side of the story. With home systems in mind, picoChip this month also introduced the PC7300, a complete femtocell hardware reference design. The PC7300 integrates all of the hardware required to implement a four- or eight-user residential femtocell, from antenna to backhaul. It includes the PCB and associated schematics and layout, populated with a picoXcell baseband processor, memory, RF circuitry and passive components.
The PC7300 is available now, reducing the total component cost of a 3G femtocell – including the picoXcell baseband device, memory, radio and PA, interface and power subsystems and PCB – to less than $50.
