UE categories in LTE

These UE categories are often referred to as UE classes. The low end UE does not support MIMO but the high end UE will support 4×4 MIMO Whatever category a UE belongs to, it has to be capable of receiving transmissions from up to four antenna ports. This is because the system information can be […]

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Traffic Operation Overview in LTE

DL Data Transmission in LTE UL Data Transmission in LTE DL and UL schedulers are running in the eNodeB.  From the following inputs, the eNodeB schedules the data on the air interface and indicates to the UE how to send (in UL) or receive (in DL) the data. Which Having Step from below to Scheduled […]

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QoS Parameters of LTE

The QoS Class Identifier (QCI) is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.). The Allocation and Retention Priority (ARP) primarily allows one to decide whether a bearer establishment request can […]

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DL & UL Physical Channel in LTE

How Physical channel of LTE works in UL & DL?A distinction has to made between:  The Physical channel The Physical signal The DL physical channels are: Physical DL Shared Channel (PDSCH) It is a shared channel used to carry user data, radio & core network, system information (BCH), paging message. Physical DL Control Channel (PDCCH) […]

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DL & UL Physical Channel in LTE, physical channels, shared channel, channel, control channel

From the Transport to the Physical Channel in LTE

Transport channels are then mapped on the physical channels which are sent over the air interface A CRC is calculated and appended to each TB. It allows the receiver to detect errors. It is used by retransmission mechanisms like H-ARQ Depending on the Transport Format and the radio quality, the TB is coded and interleaved. […]

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Spreading Technology in WCDMA

Spreading consists of 2 steps: Channelization operation, which transforms data symbols into chips Scrambling operation is applied to the spreading signal Spreading means increasing the bandwidth of the signal beyond the bandwidth normally required to accommodate the information. The spreading process in UTRAN consists of two separate operations: channelization and scrambling. The first operation is […]

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How Transport Channel Work in LTE?

A transport channel defines how and with what characteristics the information is transmitted. Inherited from the WCDMA, data on the transport channel is organized into “Transport Blocks”, TBs. A Transport block can be transmitted every TTI = 1 ms The “Transport Format”, TF, defines how the blocks can be transmitted: Transport block size, it depends […]

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How Transport Channel Work in LTE?, channel, characterized, transport channels, broadcast, shared channel, link adaptation

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 […]

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Spectrum Analysis of Spreading & Dispreading in WCDMA-3G, Spectrum Analysis, radio, communication, systems, transmit data

Correlation in WCDMA

How Correlation works in WCDMA ? Correlation measures similarity between any two arbitrary signals. Identical and Orthogonal signals: Correlation is used to measure similarity of any two arbitrary signals. It is computed by multiplying the two signals and then summing (integrating) the result over a defined time windows. The two signals of figure (a) are […]

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Correlation in WCDMA, wcdma basic, signalling, telecom wcdma techniques

How Many Logical Channel in LTE ?

The following control logical channels have been defined by the 3GPP: BCCH, Broadcast Control Channel, used for the transmission of system control information. A UE needs to decode it before requesting a connection. PCCH, Paging Control Channel, is a downlink channel that transfers paging information and system information change notifications. This channel is used for […]

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WCDMA Interleaving

How WCDMA Interleaving ? Effect Interleaving is used to reduce the probability of consecutive bits error Longer interleaving periods have better data protection with more delay Channel coding works well against random errors, but it is quite vulnerable to bursts of errors, which are typical in mobile radio systems. The especially fast moving UE in […]

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WCDMA Interleaving, bits error, data protection, wcdma basic, wcdma control

WCDMA Channel Coding

Effect Enhance the correlation among symbols so as to recover the signal when interference occurs Provides better error correction at receiver, but brings increment of the delay Channel Types No Coding Convolutional Coding (1/2, 1/3) Turbo Coding (1/3)   UTRAN employs two FEC schemes: convolutional codes and turbo codes. The idea is to add redundancy […]

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WCDMA Channel Coding, turbo code, convolution code, wcdma advance, wcdma bsic, wcdma codes planning

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