Definition: The Long Code (LC) PN generator consists of 42 binary shift-register stages. The LC_STATE is the set of 42 binary-bit values which give the binary state (one or zero) of each of the 42 shift-register stages. Once the LC_STATE is specified at a certain time, the future states of the 42 shift registers of the generator are known perfectly. Hence, the future spreading, scrambling, masking, and data burst randomizer functions are also known perfectly. The LC_STATE is communicated to the mobiles by the synchronization message. The individual masks assigned to the mobiles cause the outputs of the long-code generator to be offset from one another and, therefore, statistically uncorrelated and separable. The long-code generator as offset by the mobiles' masks combine to produce the uniquely identifiable channels on the reverse link.
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© 1999 DR. ERNEST SIMO - SPACE2000
LC_STATE
Application:
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© 1999 DR. ERNEST SIMO - SPACE2000
LC_STATE
Example: Any binary vector or word with 42 bits, other than the all zero state, will at some time during the period of the generator be the value of LC_STATE. The long-code generator has a chip period of 242-1, about 4.398x1012, which at the chipping rate of 1.2288 Mchips/sec produces a time period of about 41.43 days.
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© 1999 DR. ERNEST SIMO - SPACE2000
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