re: W-CDMA: China's No. 1 Son?It is easy to chang the current mobil systems form GSM to WCDMA than TD-SCDMA in China. Since TD-SCDMA adopt more complex tech such smart antenna than WCDMA. Now, the smart antenna has caused great system implementation complexity, which is difficult for the practical base station products. However, for WCDMA, if it adopts STS tech, it will face similar problems. Our simulation shows that STS is also difficult to put into use at base stations.
re: W-CDMA: China's No. 1 Son?yangxiao, can you give us a few more details i=on the complexity increase for TD-SCDMA vs. WCDMA? Would love to see some real information on this suject that is so often lost in deep politics
re: W-CDMA: China's No. 1 Son?I said that TD-SCDMA with more complexity than WCDMA, based on following reasons:
1.TD-SCDMA base station has a cicular array antenna with 8 elements; 2. TD-SCDMA base station needs to provide space beam to 48 mobil acitve users in a cell at same time; 3. there are many problems are caused by the smart anttena: a. cicular array antenna only has lower space solutions, which lead to the space beams are overlaps; b. TD-SCDMA base receivers and transmitters need tracking the users; space position; c. if the users cross into another cell, two base stations need tracking the user and switching their space beam; d. the above problems will lead to revise some phisical layers and air interfaces; e. now, the above problems have not been solved.
Thus the TD-SCDMA has much more complexity than WCDMA.
In many respects I think you are right. This is a complex system, and probably the first system where smart antennas are included in the standard.
However, you have described the commonest implementation (Siemens / Datang 8-antenna circular) and not all of those features are actually required in the TD-SCDMA standard.
It would be possible to design a simpler implementation that was still standard compliant.
For example, a 3-sector system (as usual cellular) with 4 antennas planar for each sector would deliver higher capacity (sectors) with less complexity in algorithms (4 antennas vs 8 in beam-forming; easier joint-detection & cancellation).
However, aside from the air-interface, there is another area where TD-SCDMA is very attractive.
WCDMA requires much more of a new core network (RNC, Iu-PS and the like), while the TD-SCDMA version ("TSM") uses far more of the GSM notwork (BSC, Gb).
This might make complexity less, and certainly has a lot of attraction for the deployment.
re: W-CDMA: China's No. 1 Son?el, I am sorry but I don't agree when you say that: > WCDMA requires much more of a new core network (RNC, Iu-PS and the like), while the TD-SCDMA version ("TSM") uses far more of the GSM notwork (BSC, Gb).
Within 3GPP both of these radio technologies are treated within the same document series and both then use the same signalling protocols between RAN and Core. You might well have seen some sort of demo network with TD-SCDMA conencted via A and Gb but this is not 3GPP compliant
1.TD-SCDMA base station has a cicular array antenna with 8 elements;
2. TD-SCDMA base station needs to provide space beam to 48 mobil acitve users in a cell at same time;
3. there are many problems are caused by the smart anttena:
a. cicular array antenna only has lower space solutions, which lead to the space beams are overlaps;
b. TD-SCDMA base receivers and transmitters need tracking the users; space position;
c. if the users cross into another cell, two base stations need tracking the user and switching their space beam;
d. the above problems will lead to revise some phisical layers and air interfaces;
e. now, the above problems have not been solved.
Thus the TD-SCDMA has much more complexity than WCDMA.
Futher detailed discussion please by E-mail.
My E-Mail: [email protected]
This is a complex subject.
In many respects I think you are right.
This is a complex system, and probably the first system where smart antennas are included in the standard.
However, you have described the commonest implementation (Siemens / Datang 8-antenna circular) and not all of those features are actually required in the TD-SCDMA standard.
It would be possible to design a simpler implementation that was still standard compliant.
For example, a 3-sector system (as usual cellular) with 4 antennas planar for each sector would deliver higher capacity (sectors) with less complexity in algorithms (4 antennas vs 8 in beam-forming; easier joint-detection & cancellation).
However, aside from the air-interface, there is another area where TD-SCDMA is very attractive.
WCDMA requires much more of a new core network (RNC, Iu-PS and the like), while the TD-SCDMA version ("TSM") uses far more of the GSM notwork (BSC, Gb).
This might make complexity less, and certainly has a lot of attraction for the deployment.
> WCDMA requires much more of a new core network (RNC, Iu-PS and the like), while the TD-SCDMA version ("TSM") uses far more of the GSM notwork (BSC, Gb).
Within 3GPP both of these radio technologies are treated within the same document series and both then use the same signalling protocols between RAN and Core. You might well have seen some sort of demo network with TD-SCDMA conencted via A and Gb but this is not 3GPP compliant