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3G technology also comes in
various forms and platforms. Understanding the major ones will help you
decide which one is the right tool. You should also tell the technical
details, to know if you are getting the right kind of efficiency and
accessibility. Getting information from the internet other various
sources will never be as convenient as fast, since 3G is the newest
available. There are new developments and changes as well to get you
ahead.
Knowing WCDMA or UMTS
W-CDMA wideband code-division multiple-access is among the major
technologies that implement the 3G or third generation cellular
systems. This is founded on the radio access technique suggested by the
ETSI Alpha Group. The details and specifications were finalized in
1999. The implementation of W-CDMA is going to be a technical challenge
due to the complexity and versatility. The sophistication of the of the
systems of W-CDMA can be seen from various aspects.
These are namely the complexity of the overall system, computation
complexity of the receiver and the complexity of ever single algorithm.
W-CDMA link-level simulations or more than 10 times the compute
intensive compared to 2G simulations. In the interface of W-CDMA, the
different interface users can immediately transmit at varying
information rates, with the data rates even varying in time. Networks
of the UMTS are required to support every 2G service, plus new services
and applications.
The Technical Details
As for the FDD technical summary, the frequency band will range from
1920 MHz up to 1980 MHz and 2110 MHz and 2170 MHz or frequency division
duplex. The minimum frequency band needed is 2 x 5 MHz. The frequency
re-use is 1. Carrier spacing is between 4.4 MHz and 5.2 MHz. The most
number of voice channels on 2 x 5 MHz is 96 with a spreading factor of
256 UL and AMR or 7.95 Kbps and 98 with a spreading factor of 128 UL
and AMR of 12.2 Kbps.
Other Specs
The voice coding includes AMR codecs ranging from 4.75 kHz up to 12.2
kHz, GSM EFR is at 12.2 kHz. SID is also included at 1.8 kHz. The
channel coding includes convolutional coding with turbo code for high
rate data. The duplexer required is 190 MHz separation with asymmetric
connection supported. Tx and Rx isolation is MS:55db and BS:80dB. The
Receiver is Rake, while receiver sensitivity is Node B.
More Information
Data type for the device is packet and circuit switch. Modulation is
QPSK and pulse shaping is root raised cosine, rolling off at 0.22. The
chip rate is 3.84 Mcps while the channel raster is 200 kHz. Maximum
user data rate on the physical channel is 2.3 Mbps with a spreading
factor of 4, and parallel codes of 3 DL / 6 UL, with limited
interference. HSPDA will provide data speeds going as fast as 8 to 10
Mps and 20 Mbps for MIMO systems. The channel it rate is 5.67 Mbps with
a frame length of 10 ms or 38400 chips.
There are 15 slots or frames, and 2560 chips. Handovers are soft and
softer, plus a hard interfrequency. The power control period has a time
slot with a rate of 1500 Hz. Power control step size is 0.5, 1, 1.5 and
2 dB while power control range is UL 80 dB and DL at 30 dB.
More on 3G: 2G to 3G Development 3G Compatibility 3G history 3G Networks 3G Now 3G Phones 3G Platforms 3G uses and features Advantages of 3G CDMA 2000 Choosing a 3G unit Evolution of Smart Phones 3G Demonstration An Introduction to 3G UMTS Uses of 3G WCDMA
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