orthogonal code
information
picture 3
The use of the CDMA method consists of a significant artificial expansion of the base of the primary signal (subscriber's voice), which is carried out in two main ways:
The use of the CDMA method consists of a significant artificial expansion of the base of the primary signal (subscriber's voice), which is carried out in two main ways:
Direct extension - direct sequence spread spectrum (DSSS)
Carrier frequency jump - frequency hop spread spectrum (FHSS)
Basic description and technical parameters of Qualcomm CDMA standard
MS signal frequency range
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824,040 – 848,970 MHz
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BTS signal frequency range
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869.040 – 893.970 MHz
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Relative instability of MS carrier frequency
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± 2,5 *10-6
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Relative instability of BTS carrier frequency
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± 5 *10-8
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Relative instability of modulation type
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QPSK (BTS), O-QPSK (MS)
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The width of the transmitted signal spectrum is 3 dBThe clock frequency of the PTK is 40 dB
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1,25 MHz
1,50 MHz
1,2288 MHz
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The number of elements in the PTKFor MS for BTS
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32768 bit
242 – 1 bit
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