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The speech coding algorithm produces a speech block of 260 bits every 20 ms (i.e. bit rate 13 kbit/s). In the decoder, these speech blocks are decoded and converted to 13 bit uniformly coded speech samples. The 260 bits of the speech block are classified into two groups. The 78 Class II bits are considered of less importance and are unprotected. The 182 Class I bits are split into 50 Class Ia bits and 132 Class Ib bits.
Class Ia bits are first protected by 3 parity bits for error detection. Class Ib bits are then added together with 4 tail bits before applying the convolutional code with rate and constraint length K=5. The resulting 378 bits are then added to the 78 unprotected Class II bits resulting in a complete coded speech frame of 456 bits.
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How do you find 125 channel in gsm?
GSM Band 890 to 915= 25 MHz One GSM Channel BW= 200 KHz Total GSM channels=25MHz/200KHz=125
What is the purpose of channel coding?
The purpose of channel coding is to maintain the frequency components in the data stream inside the bandwidth determined by the TX loop filter and RX filter.
Differentiat between source coding and channel coding?
Source Coding : this is done to reduce the size of the information (data compression) being transmitted and conserve the available bandwidth. This process reduces redundancy. e.g. zipping files, video coding (H.264, AVS-China, Dirac) etc. Channel Coding : this is done to reduce errors during transmission of data along the channel from the source to the destination. This process adds to the redundancy of data. e.g. Turbo codes, convolutional codes etc.
What is the color code for the dimm slots?
Color coding is used to identify the channel.
What is the full bit rate per voice channel in GSM?
270.83 kbps
What is Packet Data Channel?
Any time-slot on any GSM radio channel assigned to GPRS usage is defined as a Packet. Data CHannel(PDCH).
What is the diffrance between source coder and channel coder?
actually the channel coding is used for the security of transmission of any digital data. and it also determines the appropriate channel for the tranmission of your message on internet
Code?
For coding
What are lapd and lapdm gsm?
link acess protocol for the D channel is used in the radio link between bts and ms
Gsm 900 vs gsm 1800?
GSM-900 and GSM-1800 are used in most parts of the world: Europe, Middle East, Africa, Australia and most of Asia. In South and Central America the following countries use the following: : :* Costa Rica - GSM-1800 :* Brazil - GSM-850, 900 and 1800 :* Guatemala - GSM-850, GSM-900 and 1900 :* El Salvador - GSM-850, GSM-900 and 1900 GSM-900 uses 890-915 MHz to send information from the mobile station to the base station (uplink) and 935-960 MHz for the other direction (downlink), providing 124 RF channels (channel numbers 1 to 124) spaced at 200 kHz. Duplex spacing of 45 MHz is used. Guard bands 100 kHz wide are placed at either end of the range of frequencies[1]. : In some countries the GSM-900 band has been extended to cover a larger frequency range. This 'extended GSM', E-GSM, uses 880-915 MHz (uplink) and 925-960 MHz (downlink), adding 50 channels (channel numbers 975 to 1023 and 0) to the original GSM-900 band. The GSM specifications also describe 'railways GSM', GSM-R, which uses 876-915 MHz (uplink) and 921-960 MHz (downlink). Channel numbers 955 to 1023. GSM-R provides additional channels and specialized services for use by railway personnel. : All these variants are included in the GSM-900 specification. GSM-1800 uses 1710-1785 MHz to send information from the mobile station to the base tranceiver station (uplink) and 1805-1880 MHz for the other direction (downlink), providing 374 channels (channel numbers 512 to 885). Duplex spacing is 95 MHz. : GSM-1800 is also called DCS (Digital Cellular Service) in the United Kingdom, while being called PCS in Hong Kong[2] (not to mix up with GSM-1900 which is commonly called PCS in the rest of the world.)
What is Antenna hopping what are the Features Which type of cabinet can accept hopping?
In antenna hopping the transmit antenna is changed during the interleaving period resulting in an increased channel diversity which can be converted into a performance gain through the channel coding.
What are the different types of coding systems?
hierarchial classification faceted classification serial coding sequential coding block coding interpretative coding mnemonic coding check digits
