Tag: hopping

  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…

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 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…

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…

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…

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…

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…

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….

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…

There are a number of relatively independent base band processing units and carrier processing units in the system. The working frequency carrier of each carrier processing unit is fixed, the…