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Cell selection and reselection in LTE UE

Cell selection and reselection in LTE UE To get service from the selected PLMN, the UE performs two types of  procedures: LTE cell selection and LTE cell reselection CELL SELECTION in LTE Upon PLMN selection, LTE UE uses “cell selection” for fast cell searching to camp on. To receive system information LTE UE tunes to … Read more

Handover Process in LTE

Handover Process in LTE In LTE, the handover process involves transferring a mobile device’s connection from one cell to another seamlessly. It includes the following key steps: Measurement: The mobile device continuously measures signal strength and quality from neighboring cells. Triggering: When certain threshold values are met, a handover is triggered. This can be due … Read more

Purpose of Channelization Code & Scrambling Code in WCDMA

Purpose of Channelization Code & Scrambling Code in WCDMA Channelization Codes in WCDMA: Channelization codes, also known as Walsh codes, serve a critical purpose in WCDMA (Wideband Code Division Multiple Access) networks. These codes are used for the spreading of user data over a wide frequency band, which is a fundamental principle of CDMA-based systems … Read more

Dedicated Control Channel (DCCH) in GSM

Dedicated Control Channel (DCCH) in GSM SDCCH (Stand-alone Dedicated Control Channel) Uplink and Downlink. Used for call setup, authentication, ciphering location update and SMS. SACCH (Slow Associated Control Channel) Downlink and Uplink. Used to transfer signal while MS have ongoing conversation on traffic or while SDCCH is being used. On the forward link, the SACCH … Read more

Types of Handover in LTE

Handovers are a crucial aspect of LTE networks, as they ensure seamless connectivity as mobile devices move within the network. Types of Handover in LTE What are the different types of handover in LTE? Intra-frequency Handover: Description: Intra-frequency handovers occur when a mobile device moves within the same frequency band and connects to a different … Read more

Forward Power Control in CDMA

Message Transmission Mode MS measures the frame quality and informs the base station to the result i.e. whether it is in the threshold or periodical  mode. Base station determines whether  to change the forward transmitting power or not. In IS-95 system, the forward power control is slow but in CDMA2000 system it is fast. Forward … Read more

Handoff Candidate Classification in CDMA

The mobile station continuously searches for Pilots to detect the presence of other CDMA signals that have the same carrier frequency and measures the strength (received Ec/Nt) of the pilots.  When the mobile station detects a Pilot of sufficient strength that is not associated with the serving cell/sector, it sends a message to the serving … Read more

How Frame Structure in Wimax ?

Mobile WiMAX frame structure Unlike Fixed WiMAX, which uses OFDM frames, Mobile WiMAX uses OFDMA frames. OFDMA allows multiple users to receive data from the base station at the same time. In this type of system, the downlink bursts from the base station are divided by a time offset and a frequency offset (sub-channel offset). … Read more

How to LTE Radio Air Interface?

The state-of-the-art design of the LTE air interface is characterised by OFDMA (DL) and SC-FDMA (UL) together with MIMO. The downlink modulation is based on OFDMA (Orthogonal Frequency Division Multiple Access). OFDMA is a variant of OFDM which has the advantage that receiver complexity is at a reasonable level, it can handle scalable bandwidth requirements … Read more

Pulse shaping and spectrum in LTE

RF engineering is a trade off between: required radio spectrum (bandwidth), speed of data transmission (bit rates) and complexity of implementation. The pulse form used to modulate complex data symbols to the radio carrier frequency is the major element of this story. Over the years several pulse forms and their associated pulse shaping filters have … Read more