 that a quarter-chip off- set gives us half the benefit of a half-chip offset. Then the average interference atten- uation of chip offset is one-quarter of the interference, 1.2 dB, as shown in Fig. 8.9. If there is a 1.2-dB opportunity with nonsynchronized chips, then why not do it in the forward direction as well? Because the advantage of a common pilot and orthogonal codes far outweighs this 1.2-dB advantage. 8.10 Conclusion The CDMA technology applies extremely sophisticated mathematics to electronic chipsets to obtain the advantages of spread-spectrum technologies. The engineers who worked to develop the original AMPS reasonably could be astounded by the sophisti- cated rake filters in CDMA user terminals, the encoding algorithms in Qualcomm chipsets, the complexity and precision of closed-loop power control, and the cooperative management of soft and softer handoffs. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. The CDMA Principle The CDMA Principle Today's CDMA may seem to be the culmination of the integration of telephony, radio engineering, and digital technology. In some ways it is. In other ways, all that has been done merely lays the groundwork for what is to come. In the next two chapters we will take a closer look at how cdmaOne is currently deployed. After that, we will look at the new 3G/UMTS standards and their effort to increase vastly the data-carrying capacity of cellular systems. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright© 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. The CDMA Principle Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright© 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given 