- Tokyo -
NEC Corporation and NEC Electronics Corporation have succeeded
in developing fundamental technology for intellectual property (IP)
cores used in wireless transceivers. The new technologies enable
embedding of IP cores into system LSIs for wireless systems, and
facilitate CMOS technology scaling of such LSIs. As a result,
customers will benefit from reduced system costs and power
consumption for next generation wireless technology solutions used
in ubiquitous networks, which can only be realized by wireless IP
digitization.
Features of the newly-developed technologies:
(1) Development of new technology that combines multiple digital
signals with various phases and amplitudes realizes lower
distortion of radio frequency (RF) signals. Applying this
technology to transmitter modulators and power amplifiers in a
wireless IP core eliminates the need for expensive external
components to reduce output signal distortion, which helps lower
total system costs for wireless transceiver systems. Furthermore,
the new technology will contribute to the shortening of wireless IP
design periods as it enables the fine tuning of wireless IP, even
after chip fabrication, through optimization of the RF signal
distortion which is achieved by controlling the digital signal
phase.
(2) Development of technology to enable direct demodulation of
digital data by comparing the sampled RF signals received in a
wireless IP core and technology to vary sampling frequency
according to the wireless communication environment.
Conventionally, a wireless receiver circuit is operated
continuously while it is receiving data. However, by applying this
technology, the operation period of receiver circuits can be
shortened, and power consumption reduced, as it allows adaptation
to the communication environment Test chip evaluation has shown
that the power is reduced by up to a tenth of that of similar
communication chips.
Enhancement of CMOS technology scaling achieves accelerated
device operation and a reduction in the thermal noise generated in
transistors, thereby promoting implementation of wireless circuits
by digital CMOS devices. However, power reduction and suppression
of RF signal degradation by process variation which is actualized
along with CMOS scaling are required, to enhance popularization of
wireless devices.
NEC and NEC Electronics’ new digital RF technology enables
further advancement of wireless circuit digitization through direct
RF signal synthesis from digital data and fine digital control of
signal processing frequency, and introduction of discrete-time
signal processing.
The new digital RF technology will enable LSI technology
scaling, fine tuning after chip fabrication, a reduction in the
number of external components and power consumption through precise
power management, and facilitate implementation of IP cores into
system LSIs for wireless systems.
The companies believe the new technology will be invaluable to
the development of ubiquitous networks, and plan to continue their
joint research toward the early realization of lower-power
consumption and lower-cost IP cores for portable and wireless
systems.
NEC will present the results of the application of this new
technology to 2.4GHz ISM-band* (ZigBee and Bluetooth) wireless IP
cores on June 14 at the 2007 Symposium on VLSI Circuits, being held
from June 14-16 in Kyoto, Japan.
Notes*
Industrial Scientific and Medical (ISM) band: is a frequency band,
in which application of wireless communication data transmission is
allowed without the permission of authorities in the industrial,
scientific, and medical areas under a certain radio power level. In
particular, the 2.4-2.5GHz band is regulated by Japan, the United
States, and the European Union.