Method and system for generation of downlink scrambling code sequence in WCDMA system

Abstract

The invention discloses a method and system for the generation of a downlink scrambling code sequence in a WCDMA (Wide Band Code Division Multiple Access) system, characterized by including the steps of: first, querying the initial position for storing the X / Y sequence state required by generating a corresponding scrambling code sequence through scrambling code offset and data length; second, sectionally abstracting partial data to perform calculation in a fast memory, and generating the X / Y state data required by a current time slot according to time slot data length movement; and finally, successively placing and outputting 32 paths of I / O scrambling code sequences generated by each time slot from a lowest bit to a highest bit by using 32 bits as a unit, wherein 2 bits represent a piece of IQ data, the lowest bit represents an I path, and the highest bit represents a Q path. The method can rapidly generate a corresponding pluralized scrambling code sequence specific to any downlink scrambling code.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a method and system for generating a WCDMA system downlink scrambling code sequence. Background technique [0002] In a WCDMA (WideBandCodeDivisionMultipleAccess, wideband code division multiple access) system, the base station determines the range of the covered cell through the coverage range of the broadcast message. Distinguishing different base stations mainly depends on different downlink scrambling codes, and each cell transmits downlink signals using different scrambling code sequences for scrambling processing. [0003] 3GPPTS25.213 (the3rdGenerationPartnerProjectTechnicalSpecifications25.213) stipulates that the scrambling code sequence is an m-sequence composed of two 18-stage shift registers X / Y, and then a Gold code sequence formed by adding the two m-sequences. The Gold code sequence is a composite code sequence of m sequences, and a new Gold code sequence w...

AI Technical Summary

Problems solved by technology

The scrambling code sequence is generated according to a single time slot. If the generated time exceeds the duration of 1 time slot, serious errors will occur in the scrambling of the transmitting end according to the time slot. In addition, if the scrambling code sequence of a single time slot is in Word (each Word32 bit) is also more memory-intensive to store

[0017] The speed of scrambling code generation directly affects the processing efficiency of the downlink channel. Although the existing technology provides several specific methods for scrambling code generation, there are defects in the generation speed, resource occupation, and power consumption.

[0018] The patent "Multi-scrambling code parallel generator and its method in WCDMA cell search" discloses a method for parallel generation of scrambling codes, but each output only generates 8 channels of I / Q data, that is, outputs 8 complex scrambling code sequences , parallel output is not efficient

[0019] "A scrambling code generator for WCDMA system and its implementation method" patent, the scrambling code generation process uses a lot of X / Y status registers, which takes up a lot of hardware resources, and only outputs 3 channels every time the scrambling code is output I / Q data, output 3 complex scrambling code sequences in parallel, low processing efficiency

[0020] "MethodandapparatusforgenerationofdownlinkscramblingcodeinwidebandCDMAmobiledevices" patent, this patent also considers segmented processing to output scrambling code sequences, but the efficiency of parallel output of scrambling codes is low

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