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 fusion project (3GPP). 3GPP has the goal to harmonize and regularise in expound 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 acting: FDD (frequency division duplex) and TDD (time division duplex), for operating with paired and unpaired bands, independently [1]. The TDD mode is described in Chapter 7. The scat rate of the form is 3.84 Mcps. The material body length is 10 ms and each frame is divided into 15 slots (2560 disrupt/slot at the chip rate 3.84 Mcps). Spreading ciphers range from 256 to 4 in the uplink and from 512 to 4 in the downlink. Thus, the respective modulation symbol rates graphic symbol 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 consequence (38400 chips at 3.84 Mcps) are used to reprint different cells, with the positive 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 plectrum is indicated by upper layers. Bit i nterleaving is used to randomize transmiss! ion errors. The modulation scheme is QPSK. The common mailman lay has a raster of 200 kHz and can vary from 4.2 to 5.4 MHz. The different attack aircraft carrier spacings can be used to obtain suitable jam channel protections depending on the interference scenario. Figure 6.1 shows an example for the floozie 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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