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US 7,257,149 B2Granted
Obtaining initial code synchronization in a CDMA communication system
AssigneeLG Electronics Inc.
InventorMin-Ho Jin
Life of this patent
Estimating the term…
Abstract
A code detector which may rapidly obtain initial code synchronization by generating different phases of a pseudo noise (PN) codes by a plurality of PN code generators. Also, the code detector implements multipliers in the code detector to perform simple and rapid multiplying operations of the output of the PN code generators.
Claims32
A method comprising:
- adding at least two distinct demodulation codes to produce a sum;
- correlating a data signal based on the sum to produce a product to generate a first correlative value;
- determining that at least one of the two distinct demodulation codes corresponds to data embodied in the data signal based on the first correlative value;
- correlating the data signal based on one of the two demodulation codes to generate a second correlative value;
- and
- determining that the other of the two demodulation codes corresponds to data embodied in the data signal based on the second correlative value.
3 more elements
An apparatus for obtaining initial code synchronization in a CDMA communication system, comprising:
- a code generator configured to generate a plurality of pseudo noise (PN) codes, adding the codes, and outputting the result;
- a multiplier configured to multiply the outputted code and a received signal;
- an integrator configured to output a first correlative value by accumulating the values outputted from the multiplier for a predetermined period of time;
- and
- a synchronization discriminator configured to individually synchronize the received signal to each of the PN codes by:
- comparing a first predetermined value to the first correlative value generated based on a summed signal of at least first and second codes;
- determining that the received signal is correlated to the second code based on the comparison;
- comparing a second predetermined value to a second correlative value generated based on the first code but not based on the second code, and
- determining that the received signal is correlated to the first code based on the comparison of the second predetermined value to the second correlative value.
6 more elements
A method for obtaining initial code synchronization in a CDMA communication system, comprising:
- obtaining a received signal and correlative energy for a predetermined period by adding two pseudo noise (PN) codes;
- comparing the correlative energy and a predetermined first critical value;
- and
- searching which one of the two codes is synchronized with the received signal if the correlative energy is higher than the first critical value as a result of the comparing.
1 more element
A method for obtaining initial code synchronization in a CDMA communication system, comprising:
- determining a correlative energy for the product of a received signal and a sum of at least two pseudo noise (PN) codes;
- comparing the correlative energy and a predetermined first critical value;
- delaying or acclerating phases of two PN codes, if the correlative energy is lower than the first critical value;
- and
- determining which code of the two PN codes is synchronized with the received signal, if the correlative energy is higher than the first critical value.
2 more elements
Dependencies are inferred from the claim text.