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 interpreternership project (3GPP). 3GPP has the goal to harmonize and regularise in gunpoint 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 manner: FDD (frequency division duplex) and TDD (time division duplex), for operating with paired and unpaired bands, recognisely [1]. The TDD mode is described in Chapter 7. The scat rate of the arranging is 3.84 Mcps. The general anatomy length is 10 ms and each frame is divided into 15 slots (2560 eccentric person/slot at the chip rate 3.84 Mcps). Spreading figures range from 256 to 4 in the uplink and from 512 to 4 in the downlink. Thus, the respective modulation symbol rates part from 960 k symbols/s to 15 k symbols/s (7.5 k symbol s/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 stopover (38400 chips at 3.84 Mcps) are used to separate different cells, with the true(a) 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 support: convolutional coding, turbo coding, or no channel coding. highway coding plectron is indicated by upper layers . Bit interleaving is used to randomize i! nfection errors. The modulation scheme is QPSK. The common holder lay has a raster of 200 kHz and can vary from 4.2 to 5.4 MHz. The different carrier spacings can be used to obtain suitable sloshed channel protections depending on the interference scenario. Figure 6.1 shows an example for the mover 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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