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Inter-Symbol Interference in LTE

Inter-Symbol Interference in LTE Definition: ISI is a phenomenon in LTE where symbols transmitted over a communication channel overlap, causing distortion in the received signal. Causes: Multipath Propagation: Signals take multiple paths with different delays, leading to overlapping symbols. Time Dispersion: Variation in signal arrival times at the receiver contributes to ISI. Impact on LTE: … Read more

What are Interference and its source, effect and types in GSM

What are Interference and its source, effect and types in GSM Interference is the sum of all signal contributions that are neither noise not the wanted signal. Lets understand how its effect, its type and what possible source for it. Effects of Interference Interference is a major limiting factor in the performance of cellular systems. … Read more

Requirement for Interference and Carrier to Interference Ratio in GSM

Requirement for Interference and Carrier to Interference Ratio in GSM GSM is an interference restricted system. Carrier-to-interference ratio (C/I), also called interference protection ratio, refers to the ratio of all useful signals to all useless signals. In GSM system, this ratio is relevant to the instantaneous location and time of MS due to irregular landform, … Read more

Inter-Carrier Interference for OFDM

The price for the optimum subcarrier spacing is the sensitivity of OFDM to frequency errors. If the receiver’s frequency is some fractions of the subcarrier spacing (subcarrier bandwidth) then we encounter not only interference between adjacent carriers, but in principle between all carriers. This is known as Inter-Carrier Interference (ICI) and sometimes also referred to … Read more

What is Interleaving

  If the voice signal is modulated and transmitted directly after channel coding, due to the condition changes in mobile communication channel, a deep of the fading will influence a successive string of bits and cause high bit error rate. If the bits of a successive string are interfered or lost, the other end of … Read more

Frequency Hopping

When the voice signal is transmitted after being processed and modulated, the frequency hopping technique will be used too, i.e. the transmission carrier varies constantly at different timeslots (of course, the variation should comply with the frequency planning principles). The frequency hopping spread spectrum (FHSS) is a method for quickly switching the transmission of radio … Read more

Burst in GSM

The Logical  Channel is used in time multiplex in a physical channel, which is categorized according to the types of messages transmitted in the physical channel. Different logical channels are used in transmission of different types of information between BS and MS, such as the signaling or traffic data. In GSM system, five different types … Read more

How Interference Diversity in GSM?

Interference is dependent on time, frequency and mobile location. Without frequency hopping, some cell planning margins must be incorporated so that sufficient service quality can still be provided in an interfered situation. By changing frequency on every TDMA frame, a mobile only experiences interference on a particular frequency once in a number of hops. Similarly, … Read more

Inter-cell interference coordination (ICIC) in LTE

Inter-cell interference coordination (ICIC) in LTE To aid downlink ICIC Relative narrowband transmission-power indicator A cell can provide this information to neighboring cells, indicating the part of the bandwidth where it intends to limit the transmission power. A cell receiving the indication can schedule its downlink transmissions within this band, reducing the output power or … Read more

Downlink Logical Channel in GSM

In 2G GSM Technology in forward direction Downlink (GSM BTS to GSM Mobile). There are mainly five Downlink Logical Channel in GSM. Frequency correction channel (FCCH) Synchronous channel (SCH) Broadcast control channel (BCCH) Paging channel (PCH) Access granted channel (AGCH) Frequency correction channel (FCCH) First start with FCCH which full form is frequency correction channel … Read more