Tag : channel coding

Downlink Logical Channel in GSM

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
Burst in GSM

Burst in GSM

The LogicalĀ  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
Definition of Logical Channel in GSM

Definition of Logical Channel in GSM

The physical channel is the medium over which the information is carried. The logical channel consists of the information carried over the physical channels. A Physical Channel (a TS, defined by a fixed position
What is Frame and Channel in GSM

What is Frame and Channel in GSM

The major basic concept concerned with the radio path transmission of the GSM system is the burst sequence (simplified as Burst). It is a string of transmission units including more than 100 modulation bits.
DTX: Discontinuous Transmission

DTX: Discontinuous Transmission

Actually, during the communication process, the mobile subscriber talks only 40% of the time and there is not much useful information transmitted during rest of the time. If all the information is transmitted to
Frequency Hopping

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
What is Interleaving

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
What is Channel Coding

What is Channel Coding

To check and correct errors during the transmission, redundancy data and the information calculated from the source data are added to the stream so as to increase the bit rate. For the voice, the
What is Speech Coding

What is Speech Coding

The coding mode is called Regular Pulse Excited-Long Term Prediction (RPE-LTP). It works as follow: 8KHZ of sampling is performed first, then divided into frames with 20ms; every frame has 4 sub-frames; the duration
Adjacent Channel Interference Ratio for LTE

Adjacent Channel Interference Ratio for LTE

It is difficult to separate Adjacent Channel Leakage power Ratio and Adjacent channel selectivity because they coexist. therefore, Adjacent Channel Leakage power Ratio and Adjacent channel selectivity are usually considered together. The result of