Secondary Synchronization Channel Sequence Segmentation for 802.16m Systems
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Solution Overview
Problem
The IEEE 802.16m wireless communication system faces challenges in distinguishing cell IDs due to deteriorated correlation characteristics and increased Peak to Average Power Ratio (PAPR) of sequences, especially when supporting a larger number of cell IDs and requiring supplementary information transmission, which affects timing synchronization and transmit power margin.
Innovation Solution
The system employs a method for generating and transmitting a Secondary Synchronization Channel (S-SCH) by determining a subcarrier set based on Fast Fourier Transform (FFT) size and segment ID, mapping sequences to these subcarriers, and using power-boosted BPSK signals to efficiently support multiple cell IDs and varying bandwidths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of sequences for cell ID distinction is increased to support more cell IDs, then the number of distinguishable cell IDs increases, but the correlation characteristics deteriorate and PAPR increases
Solution Approach 1:
The S-SCH sequences are divided into multiple sequence blocks, where each block contains a specific number of sequences. This segmentation allows the system to support a large number of cell IDs (up to 768) while maintaining good correlation characteristics within each block, thereby resolving the contradiction between supporting more cell IDs and maintaining detection performance.
Solution Approach 2:
The patent changes the structure and parameters of the S-SCH sequences by defining specific sequence blocks with controlled lengths and relationships. This parameter optimization ensures that even with a large total number of sequences for many cell IDs, the correlation characteristics within each block remain favorable for detection.
2Measurement precision
If the number of sequences for cell ID distinction is increased to support more cell IDs, then the number of distinguishable cell IDs increases, but the PAPR increases reducing transmit power margin
Solution Approach 1:
By segmenting the sequences into blocks and carefully designing the structure of each block, the patent reduces the PAPR of individual sequences. This allows the system to support many cell IDs while maintaining lower PAPR values, thereby preserving transmit power margin and resolving the contradiction between cell ID capacity and power efficiency.
3Measurement precision
If a repetition pattern of SCH is used for timing synchronization, then timing synchronization is achieved, but at cell boundaries the repetition pattern is broken by adjacent cell interference
Solution Approach 1:
The patent extracts the timing synchronization function from the traditional repeated SCH pattern and implements it through correlation-based detection of S-SCH sequences. By removing the problematic repetition structure and using sequence correlation instead, the system achieves reliable timing synchronization even at cell boundaries where adjacent cell interference would normally break the repetition pattern.
4Adaptability or versatility
If power-boosted BPSK signals are used for S-SCH transmission, then support for multiple cell IDs and varying bandwidths is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic adaptability by allowing the S-SCH to be transmitted with power-boosted BPSK signals that can be configured for multiple cell IDs and varying bandwidths. The system dynamically selects appropriate sequence blocks and transmission parameters based on the specific deployment scenario, achieving high versatility while managing complexity through structured design.
Data Source
AI summary
An apparatus and method for transmitting/receiving an S-SCH in an Institute of Electrical and Electronics Engineers (IEEE) 802.16m wireless communication system are provided. A method for transmitting, by a transmitter, a Secondary Synchronization CHannel (S-SCH) in a communication system includes generating a sequence depending on a cell IDentification (ID), determining a subcarrier set comprising subcarriers to map the generated sequence, based on a Fast Fourier Transform (FFT) size and a segment ID, and mapping the generated sequence to the subcarriers of the determined subcarrier set.