Wireless and Cellular Telecommunications, Third Edition
Just in time for the rebounding wireless industry, this updated classic text offers an in-depth engineering guide for both voice and data services, Wi-Fi, 3G, WiMAX, and more.
TABLE OF CONTENTS Wireless and Cellular Telecommunications, Third Edition
4.4: CDMA
4.4 CDMA
CDMA development [26] [27] [28] [29] [30] started in early 1989 after the NA-TDMA standard (IS-54) was established. A CDMA demonstration to test its feasibility for digital cellular systems was held in November 1989. The CDMA "Mobile Station-Base Station Compatibility Standard for Dual Mode Wideband Spread Spectrum Cellular System" was issued as IS-95 (PN-3118, Dec. 9, 1992). CDMA uses the idea of tolerating inteterference by spread-spectrum modulation. The power control scheme in a CDMA system is a requirement for digital cellular application. However, it was a challenging task and has been solved. Before describing the structure of the system, we list the key terms of CDMA systems.
4.4.1 Terms of CDMA Systems
Active set: The set of pilots associated with the CDMA channels containing forward traffic channels assigned to a particular mobile station (MS).
CDMA channel number: An 11-bit number corresponding to the center of the CDMA frequency assignment.
Code channel: A subchannel of a forward CDMA channel. A forward CDMA channel contains 64 code channels. Certain code channels are assigned to different logic channels.
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Code channel zero: Pilot channel.
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Code channels 1 through 7: Either paging channels or traffic channels.
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Code channel 32: A sync channel or a traffic channel.
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The remaining code channels are traffic channels.
Code symbol: The output of an error-correcting encoder.
Dim-and-burst: A frame in which the primary traffic is multiplexed with either secondary traffic or signal traffic. It is equivalent to the blank-and-burst function in AMPS.
Forward CDMA channel: Contains one...
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