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Orthogonal Code Usage – Coding & Decoding in WCDMA

How Orthogonal Code works in WCDMA? 1.Coding By spreading, each symbol is multiplied with all the chips in the orthogonal sequence assigned to the user. The resulting sequence is processed and is then transmitted over the physical channel along with other spread symbols. In this figure, 4-digit codes are used. The product of the user … Read more

Spectrum Analysis of Spreading & Dispreading in WCDMA-3G

How Spreading & Dispreading in WCDMA-3G ? Traditional radio communication systems transmit data using the minimum bandwidth required to carry it as a narrowband signal. CDMA system mix their input data with a fast spreading sequence and transmit a wideband signal. The spreading sequence is independently regenerated at the receiver and mixed with the incoming … Read more

Physical Random Access Channel PRACH work for WCDMA

PRACH Physical Random Access Channel work in WCDMA Carrying uplink signaling and data, consist of two parts: One or several preambles: 16 kinds of available preambles 10 or 20ms message part The Physical Random Access Channel (PRACH) is used by the UE to access the network and to carry small data packets. It carries the … Read more

Active Distributed Antenna Systems inside 3G

A DAS contains the same active components present in a DAS passive, with the addition of active devices such as amplifiers, repeaters or amplifiers bidirectional (BDAS) to amplify and / or radio signals shipping. This enables an active DAS to cover a much larger area of ​​a passive DAS. Active distribution systems, however, are more … Read more