15.01.2013 Views

U. Glaeser

U. Glaeser

U. Glaeser

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Technological hurdles must be overcome in the road toward Bluetooth IP block solutions. Presently,<br />

the RF front-end solutions for bluetooth are nearly all implemented in bipolar IC technology, implying<br />

at least a BiCMOS IC, which is widely recognized as too high cost for high-volume SoC products. As the<br />

lithography becomes available for denser CMOS IC products, the deep submicron devices provide the<br />

density and speed increases to support SoC solutions in the digital arena, and also improve the frequency<br />

response of the analog circuitry, enabling the possibility of future all-CMOS implementation.<br />

In addition, communications system problems must be solved in order to ensure the feasibility of an<br />

all-CMOS implementation. For example, one of the more popular architectures for a modern communications<br />

receiver is the zero-IF (ZIF) approach. Unfortunately, the ZIF approach usually converts the<br />

RF energy immediately to baseband without significant amplification, which places the very small signal<br />

in the range of 1/f noise of the semiconductor devices employed. Typically, the only devices with<br />

substantially low enough noise are bipolar devices, which are to be avoided for system level considerations.<br />

Alternative architectures that are suitable include variants of super heterodyne architectures that usually<br />

require tuned amplifiers, which are also seldom suitable for integration. One approach that seems to<br />

meet all the requirements is one variant of the super heterodyne architecture known as low-IF, that places<br />

the energy high enough in the spectrum to avoid noise considerations, but low enough to be addressed<br />

by DSP processing to achieve the requisite filtering.<br />

Regardless of the particular architecture chosen, the rapid channel switching involved in the frequencyhopping<br />

scheme necessitates frequency synthesis for local oscillator functions. There is considerable design<br />

challenge in developing a fully integrated voltage-controlled-oscillator (VCO) for use in a synthesizer<br />

that slews rapidly and still maintains low phase noise.<br />

To compound the above issues, true IP block portability implies a level of process independence that<br />

is not currently enjoyed by any of the available architectures. Portability issues are likely to be addressed<br />

by intelligence in the CAD tools that are used to customize the IP blocks to the target process through<br />

process migration and shrink paths.<br />

References<br />

1. Bluetooth is a trademark owned by Telefonaktiebolagent L M Ericsson, Sweden and licensed to the<br />

promoters and adopters of the Bluetooth Special Interest Group.<br />

2. http://www.bluetooth.com/developer/specification/specification.asp Bluetooth Specification v1.1 core<br />

and v1.1 profiles.<br />

3. http://www.bluetooth.com/sig/sig/sig.asp Bluetooth Special Interest Group (SIG).<br />

4. Infrared Data Association IrDA http://www.irda.org.<br />

5. Bray, J. and Sturman, C.F., Bluetooth, Connectivity with our Cables, Prentice-Hall, Englewood Cliffs,<br />

NJ, 2001.<br />

6. Miller, B.A. and Bisdikian, C., Bluetooth Revealed, Prentice-Hall, Englewood Cliffs, NJ, 2001.<br />

7. Tseng , Y., Wu, S., Liao, W., and Chao, C., Location Awareness in Ad Hoc Wireless Mobile Networks.<br />

[June 2001], IEEE Computer, 46,52.<br />

8. International Origination of Standardization Information processing systems–Open Systems<br />

Interconnection–Connection Oriented Transport Protocol Specification, International Standard<br />

number 8825, ISO, Switzerland, May 1987.<br />

9. Held, G., Data Over Wireless Networks, McGraw-Hill, New York, 2001.<br />

10. http://www.comtec.sigma.se/Ericsson’s Bluetooth Application and Training Tool Kit 200.<br />

11. BlueCore” and BlueStack” are registered trademarks of Cambridge Silicon Radio, Cambridge,<br />

England, 2001.<br />

12. http://www.csr.com/software.htm, Development software for BlueCore ICs Cambridge Silicon<br />

Radio, Cambridge, England, 2001.<br />

13. Dornan, A., Wireless Ethernet: Neither Bitten or Blue. Network Magazine, May 2001.<br />

14. Merritt, R., Conflicts Between Bluetooth and Wireless LANs Called Minor. EE Times,<br />

February 2001.<br />

15. Muller, N.J., Bluetooth Demystified, McGraw-Hill, New York 2000.<br />

© 2002 by CRC Press LLC

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!