HS-DSCH Code Multiplexing for 64QAM Bit Interleaving
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current High Speed Downlink Shared Channel (HS-DSCH) technologies, based on CDMA, face limitations in meeting increasing demands for broader transmission bandwidth and higher speeds due to multi-path interference, and are unable to effectively support 64QAM, which is necessary for improved spectral efficiency and peak rates.
Innovation Solution
The method involves segmenting the physical channel into multiple sequences, interleaving them using specific interleaver sizes, and implementing constellation rearrangement to enhance the reliability of bit sequences, allowing for the use of 64QAM in HS-DSCH coding and multiplexing, thereby improving transmission performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CDMA-based HSDPA technology is used, then spectral efficiency and transmission speed are improved, but multi-path interference limits further bandwidth and speed expansion
Solution Approach 1:
The physical channel bit sequence is segmented into multiple sequences (e.g., 2 or 3 sequences), with each sequence processed by separate interleavers. This segmentation allows the system to handle 64QAM modulation more effectively by distributing bits across multiple interleaved sequences, thereby improving spectral efficiency and transmission speed while mitigating multi-path interference through diversified bit placement patterns
2Productivity
If 64QAM is implemented in HS-DSCH, then spectral efficiency and peak rates are improved, but the existing coding and multiplexing framework cannot support it
Solution Approach 1:
The bit sequence for 64QAM is divided into multiple sequences, with each sequence processed by dedicated interleavers of specific sizes (e.g., 32×30 or 48×30). This segmentation enables 64QAM support by organizing the 6 bits per symbol into manageable groups that can be independently interleaved and protected, making high-order modulation compatible with the existing HSDPA framework
Solution Approach 2:
Different interleaving schemes are applied to different bit sequences within the same channel, with specific interleaver sizes (32×30 or 48×30) selected based on the sequence position and content. This local differentiation optimizes the protection and arrangement of bits for 64QAM while maintaining compatibility with existing system constraints
3Reliability
If bit sequences are segmented and interleaved with constellation rearrangement, then transmission reliability is improved, but processing complexity increases
Solution Approach 1:
The bit sequence is divided into multiple sequences that are independently interleaved using standardized interleaver dimensions (32×30 or 48×30). This segmentation improves reliability by ensuring that burst errors affect only limited portions of each sequence, while the modular structure keeps processing complexity manageable through reuse of existing interleaver implementations
Solution Approach 2:
The interleaver dimensions are changed to specific values (32×30 or 48×30) that are optimized for 64QAM performance. These parameter changes improve bit sequence reliability by creating optimal error distribution patterns, while the standardized nature of these parameters allows efficient implementation without excessive complexity increase
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A code multiplexing method for High Speed Downlink Shared Channel is provided, when Hybrid Automatic Repeat Request bits combination are processed using 64 Quadrature Amplitude Modulation. The method includes: when interleaving after a segmentation of physical channel, dividing the bit sequence obtained from the segmentation of physical channel into at least two sequences, which are interleaved through interleavers with the same size respectively. The technical scheme provided in the present invention can use 64 QAM based on the HS-DSCH code multiplexing technology, therefore, the transmission performance for HS-DSCH is improved.