Contents
What is the importance of 26 training bits?
26 bits training sequence: This training sequence is used as a timing reference and for equalisation. There is a total of eight different bit sequences that may be used, each 26 bits long.
What is the duration of guard time in GSM?
The GSM standard [1] specifies a TDMA frame as a combination of 8 time slots. Each time slot has a duration of 3/5200 seconds (about 0.577 ms) and a time slot number (TN) from 0 to 7. GSM frames use GMSK modulation, where one symbol is equivalent to one bit. Each time slot is 156.25 bits long.
How many types of burst are there in GSM?
Five different types
Burst Structure Five different types of bursts are used for transmission in GSM. The normal burst is used to carry data and most signaling.
Which of the following GSM channel is used on downlink only?
i) Paging channel (PCH): Downlink only, used to page mobiles.
What is GSM frame structure?
The GSM frame structure is designated as hyperframe, superframe, multiframe and frame. The minimum unit being frame (or TDMA frame) is made of 8 time slots. One GSM hyperframe composed of 2048 superframes. Each GSM superframe composed of multiframes (either 26 or 51 as described below).
What is training sequence code in GSM?
GSM defines nine groups of training sequence code (TSC) [12] for NB; eight groups of which are used for the cell traffic channel. The downlink timeslot signal of different cells using the same carrier frequency can use different training sequences to make the distinction.
What is the frame rate of GSM?
A GSM Multiframe is the basic unit, and is 120 ms long. There are 26 Frames in each Multiframe, with each Frame being 4.61538 ms long (120 ms/26). Within each Frame are 8 Timeslots at 576.92 μs per Timeslot (577 μs in round numbers). Finally, there are 156.25 Bits per Timeslot, each Bit being 3.69231 μs long.
What are the control groups in GSM?
In GSM networks, Control Channels are divided into three categories: Broadcast Channel (BCH), Common Control Channel (CCCH), and Dedicated Control Channel (DCCH).
What is frame rate in GSM?
What is training sequence?
The training sequence known as reference signal is used for the channel equalization in time domain when receiving signals for each cell, so that it can improve the anti-interference ability of GSM mobile communication system.
What is duration of GSM Sacch multi frame?
– a 51-frame multiframe (26 per superframe) with a duration of ≈ 235,4 ms (3 060/13 ms), comprising 51 TDMA frames. This multiframe is used to carry BCCH, CCCH (NCH, AGCH, PCH and RACH) and SDCCH (and SACCH/C). A TDMA frame, comprising eight time slots has a duration of ≈ 4,62 (60/13) ms.
Which is the minimum unit for a GSM frame?
This is explained below in TDMA gsm frame structure. For E-GSM number of ARFCNs are 174, for DCS1800 ARFNCs are 374. The GSM frame structure is designated as hyperframe, superframe, multiframe and frame. The minimum unit being frame (or TDMA frame) is made of 8 time slots.
How many time slots are in a GSM hyperframe?
The minimum unit being frame (or TDMA frame) is made of 8 time slots. One GSM hyperframe composed of 2048 superframes. Each GSM superframe composed of multiframes (either 26 or 51 as described below). Each GSM multiframe composed of frames (either 51 or 26 based on multiframe type).
What are the duration of GSM Training codes?
The GSM training sequence codes have a duration of 26 Gaussian minimum shift keying (GMSK) symbols, which is equal to (26/156.25) × 577 = 96 μs; experience shows that 20% of signal duration used in sliding window could ensure the effective signal detection.
How many frames are there in a GSM superframe?
Each GSM superframe composed of multiframes (either 26 or 51 as described below). Each GSM multiframe composed of frames (either 51 or 26 based on multiframe type). Each frame composed of 8 time slots. Hence there will be total of 2715648 TDMA frames available in GSM and the same cycle continues.
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