Wcdma

Chapter 6 WCDMA Chapter 6 6.1 INTRODUCTION This chapter presents the WCDMA air interface, referred also as UMTS terrestrial radio access (UTRA), substantial by the third-generation league project (3GPP). 3GPP has the goal to harmonize and regularise in exposit the similar proposals from ETSI, ARIB, TTC, TTA, and T1. Table 6.1 lists the parameters of WCDMA. WCDMA has two modes characterized by the duplex method: FDD (frequency division duplex) and TDD (time division duplex), for operating with paired and unpaired bands, enlightenly [1]. The TDD mode is described in Chapter 7. The scat rate of the carcass is 3.84 Mcps. The skeleton length is 10 ms and each frame is divided into 15 slots (2560 bank check/slot at the chip rate 3.84 Mcps). Spreading constituents range from 256 to 4 in the uplink and from 512 to 4 in the downlink. Thus, the respective modulation symbol rates sort out from 960 k symbols/s to 15 k symbols/s (7.5 k symbols/s) for FDD uplink . For separating bring from the same source, orthogonal variable spreading factor (OVSF) channelization codes are employ. In the downlink, grand codes with a 10-ms plosive (38400 chips at 3.84 Mcps) are used to separate different cells, with the certain code itself length 218-1 chips.

In the uplink, Gold codes with a 10ms period, or alternatively short codes with a 256-chip period, are used to separate the different users. For the channel coding tercet options are back up: convolutional coding, turbo coding, or no channel coding. highway coding plectron is indicated by upper layers. Bit interleaving is used to randomize infection errors. Th! e modulation scheme is QPSK. The common pallbearer lay has a raster of 200 kHz and can vary from 4.2 to 5.4 MHz. The different crew cut spacings can be used to obtain suitable stodgy channel protections depending on the interference scenario. Figure 6.1 shows an example for the operator bandwidth of 15 MHz with three cell layers. Larger carrier spacing can be applied...If you want to get a full essay, mold it on our website: OrderCustomPaper.com

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