RTX has now TD-SCDMA handset platform – the most competitive on the market

Cost of TD-SCDMA is less expensive than CDMA and UMTS

There has been a lot of speculation about when Chinese authorities will issue 3G licenses, and whether the standard will be WCDMA, CDMA2000 or the homegrown TD-SCDMA. The expected selection of TD-SCDMA will also give a boost to the Chinese wireless industry and bring China into the league of countries which are defining the future of the wireless industry. Another reason for the authorities’ support for TD-SCDMA has been that TD-SCDMA royalties are lower than WCDMA. Additionally, the bill of materials for TD-SCDMA handsets is substantially lower than other 3G handsets and only slightly more expensive than GSM/ GPRS terminals.

TD-SCDMA is the only 3G standard adopted by all six telecom operators. The Chinese government is allowing mobile operators to make their own decision on which 3G wireless technology to deploy. At the present time, TD-SCDMA is the only standard, which has been adopted by all six telecom operations for testing. China Mobile and China Unicom have been involved in setting up a test-network in Shanghai and Beijing, which will end testing in September 2004. This means that a stable network is not expected before Q2 2005, so the first terminals will be on the market in the middle of 2005.

Multimode support will be essential

With the popularity of GSM in China and the scattered coverage during the introduction of TD-SCDMA networks, a TD-SCDMA terminal will be required to revert to GSM outside of areas with TD-SCDMA coverage. One major difference in TD-SCDMA is the employment of a multi-user detection receiver instead of the rake receiver used in W-CDMAand CDMA2000. Because TD-SCDMA only has 16 active codes, it is possible to detect them all. This provides better spectrum efficiency than other 3G cellular technologies. Further improvements will be possible in the future as digital signal processor (DSP)technologies become more sophisticated and parts of the joint detection algorithm can be implemented in an acceleration unit inside the DSP. For more information about the joint detection algorithm, see the technical articles on our website.

Optimum Spectrum Efficiency

A lot of radio technologies, such as GSM and UTRA-FDD, require two separate bands for uplink and downlink with a separation between the bands. TDD-based technologies use a common band for uplink and downlink. Uplink and downlink traffic can then be transmitted on the same carrier frequencies but in different time slots. Adaptive allocation of radio resources to uplink and downlink is one key to optimised spectrum efficiency, achieved by the TDD operation of TD-SCDMA. Furthermore, the small bandwidth of 1.6 MHz technology allows flexible allocation of the spectrum.

Low Chip Rate (LCR) protocol stacks support handover to GSM

The time-division duplex LCR (TDD-LCR) protocol stack, based on the ITU 3rd Generation Planning Partnership Project UTRA irinterface (3GPP) standard, has been chosen. By using the 3GPP standards full compatibility to GSM and W-CDMA is secured and making handover possible to both GSM and even to W-CDMA.

Data rates up to 2 Mbit/s

With 2Mbit/s TD-SCDMA offers sufficient bandwidth to handle the data traffic for multimedia and Internet applications for the future, although first generations of TD-SCDMA terminals will, like W-CDMA terminals, have a lower data rate.

RTX has the most competitiveplatform in the industry

Together with a leading chip-set manufacturer, RTX has developed the first chipset for TDSCDMA. RTX is currently developing the first commercial TD-SCDMA handsets based on the chipset, and expects to have the handset ready for the market in mid-2005, when the launch of the TD-SCDMA networks is anticipated. The interoperability testing will commence in Q3 2004 on the TD-SCDMA networks  in China. The RTX TD-SCDMA platform is believed to be the most competitive in the industry from a bill of materials and number of components point of view.