PN Sequence Initialization Under 31-Bit Constraints in 5G NR
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Solution Overview
Problem
The direct usage of LTE PN sequences in 5G NR systems faces issues due to the excess initialization value configuration, which exceeds the 31 bits required for an LTE Gold sequence, leading to a lack of bits to represent the initialization value effectively, especially with the increased number of cell-IDs and OFDM symbols in NR systems.
Innovation Solution
The solution involves generating PN sequences for NR systems by transforming the long initialization value into a compressed value using hashing functions like CRC or cyclic wrap around, initializing the first M-sequence with a fixed value, and the second M-sequence with the compressed value, ensuring the initialization value fits within the 31-bit limit, while maintaining the necessary randomness and randomization across time instances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LTE PN sequences are directly used in 5G NR systems, then hardware efficiency and network coverage are improved through reuse, but the initialization value configuration exceeds the 31-bit limit required for LTE Gold sequences
Solution Approach 1:
The patent extracts only the necessary portion of the initialization value by using modulo operation to obtain the lower 31 bits, discarding the excess higher bits that cause the contradiction. This allows the NR system to use LTE PN sequences while fitting within the 31-bit constraint.
Solution Approach 2:
The patent transforms the initialization value parameter by applying mathematical operations (modulo 2^31) to change its representation from a potentially large value to a standardized 31-bit value, enabling compatibility with LTE hardware while maintaining NR system requirements.
2Device complexity
If the initialization value is compressed to fit 31 bits, then the bit representation constraint is satisfied, but the randomness and randomization across time instances may be reduced
Solution Approach 1:
The patent applies preliminary transformation to the initialization value using hashing functions or modulo operations before it is used to generate the PN sequence. This pre-processing ensures the value fits the 31-bit constraint while preserving the essential randomization properties needed for reliable communication.
Solution Approach 2:
The patent introduces an intermediary transformation process (hashing function or modulo operation) that mediates between the NR system's need for larger initialization values and the LTE hardware's 31-bit constraint, preserving randomness through the transformation.
Data Source
AI summary
Embodiments of the present disclosure describe apparatuses, systems, and methods for initialization of pseudo noise (PN) sequences for reference signals and data scrambling. Some embodiments may be to initialize the first M-sequence of the PN sequence with a fixed value; and initialize the second M-sequence of the PN sequence with a compressed value. Some embodiments may be to initialize the first M-sequence of the PN sequence with a fixed value; initialize the second M-sequence of the PN sequence with a part of the initialization parameters; and shift the PN sequence by another part of the initialization parameters. Some embodiments may be to initialize the first M-sequence of the PN sequence with a part of the initialization parameters; and initialize the second M-sequence of the PN sequence with another part of the initialization parameters. The embodiments may lead to a more efficient hardware design.