Understanding WCDMA
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.
About the CDMA2000
There are different platforms or types of 3G technology. Each manufacturer has created and developed some of the most innovative products and mobile handsets. The CDMA2000 is one of the 3 major types. It has different features and tools also that will surely give you a whole new experience, unlike other technologies before it. Here are the details on how to make the most out of the specification.
Introduction
The CDMA2000 specification was created and developed by the Third Generation Partnership Project 2 or 3GPP2, which is a partnership that consists of 5 telecommunication standard bodies: TTC and ARIB in Japan, TTA in Korea, TIA in North America and CWTS in China. CDMA2000 has been implemented to a lot of networks as an evolutionary step from CDMAOne. CDMA2000 gives a full backward compatibility with IS-95B.
CDMA2000 is not contained only into a single IMT-2000 and, although managers have the ability to overlay ACDMA2000 1x system. The system backs 144 Kbps at present, with data rates running up to 307 Kbps in the near future, over the other present CDMAOne network.
Evolving the Technology
CDMA2000 1xEV is the other name of the evolved CDMA2000. This technology will be implemented via a number of steps, namely the 1xEV-DV and 1xEV-DO. 1xEV-DO which represents 1x Evolution Data Only. 1xEV-DV represents 1x Evolution Data and Voice. The two 1xEV CDMA2000 evolution steps will use a carrier standard 1.25 Mhz. 1xEV-DO will most likely be available for the operators CDMA2000 during 2002. The solutions for 1xEV-DV were made available in 2004.
CDMA2000 3x and CDMA2000 1x EV-DO are approved by ITU and IMT-2000 3G basics. CDMA2000 3x is a portion of what the ITU has called IMT-2000 CDMA MC or Multi Carrier. This uses a lower than 5 MHz spectrum via 3x 1.25 MHz channels to provide speeds of more than 2 Mbps.
The Technical Summary
As for the summary of the CDMA2000, the frequency band can be any type or existing and. The minimum frequency band needed for 1x is 2 x 1.25 MHz. For 3x, the required is 2 x 3.75 Mhz. Chip rate for 1x is 1.2288. For 3x, chip rate is 3.6864 Mcps.
The maximum user data rate for 1x is 144 Kbps at present and 307 Kbps in the near future. As for 1xEV-DO, the max rate is 384 Kbps to 2.4 Mbps. The frame length is 5 ms, 10 ms or 20 ms. As for power control rate, it is at 800 Hz. The spreading factors are 4 256 UL.
On WCDMA
W-CDMA in 3G is known as wideband code division multiple access. It is one of the main technologies used for the implementation of 3G cellular systems. It is founded on the radio access method give by ETSI Alpha group with the features and specifications finalized in 1999.
The implementation of W-CDMA will cover very technical details. The complexity of the systems can be seen from various angles. These include the complexity of the receiver, the complexity of the overall system and the complexity of the single algorithm.
In W-CDMA, the interface allows users of 3G to instantly send and get various data rates. UMTS networks will need the support of all current 2G services and several new services and applications. You should consider if this will be the right technique for you.
