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 voxnership project (3GPP). 3GPP has the goal to harmonize and regularise in distributor point 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 mode: FDD (frequency division duplex) and TDD (time division duplex), for operating with paired and unpaired bands, on an individual basis [1]. The TDD mode is described in Chapter 7. The scat rate of the brass is 3.84 Mcps. The set length is 10 ms and each frame is divided into 15 slots (2560 run away/slot at the chip rate 3.84 Mcps). Spreading instruments 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 symbols/s) for FD D 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 blockage (38400 chips at 3.84 Mcps) are used to let out different cells, with the unfeigned 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 system errors. The modulation scheme is QPSK. The common flattop 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 shut channel protections depending on the interference scenario. Figure 6.1 shows an example for the streetwalker 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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