PRACH Occasion Determination Using SS/PBCH Timing Indices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication systems, such as LTE and emerging New Radio (NR) standards, face challenges in efficiently managing random access preambles and determining PRACH occasions for terminal apparatuses and base stations, particularly in scenarios requiring enhanced Mobile BroadBand, massive Machine Type Communication, and Ultra Reliable and Low Latency Communication.
Innovation Solution
The solution involves a terminal apparatus and base station apparatus that determine PRACH occasions based on specific relationships between timing indices and indices of DMRS for PBCH blocks, using remainders from dividing timing indices by a number included in the MIB, to efficiently transmit and receive random access preambles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple SS/PBCH block candidates are transmitted to support multiple scenarios (eMBB, mMTC, URLLC), then communication versatility is improved, but device complexity and resource management difficulty increase
Solution Approach 1:
The patent segments the random access resources by associating different SS/PBCH block candidates with different PRACH occasions. The terminal determines which PRACH occasion to use based on the detected SS/PBCH block index, effectively dividing the random access resource space into multiple segments. This segmentation allows the system to support multiple communication scenarios (eMBB, mMTC, URLLC) simultaneously while maintaining organized resource management, as each scenario can be mapped to specific PRACH occasions without interfering with others.
2Measurement precision
If PRACH occasions are determined using complex relationships involving timing indices and DMRS indices, then random access precision is improved, but terminal processing complexity increases
Solution Approach 1:
The patent enables the terminal to self-determine the appropriate PRACH occasion by using the detected SS/PBCH block index directly in the determination process. The terminal autonomously calculates the PRACH occasion index using the formula involving the SS/PBCH block timing index and the QSSB parameter, without requiring additional base station instructions or complex external coordination. This self-service mechanism reduces signaling overhead and simplifies the overall system complexity while maintaining precise PRACH occasion determination.
3Reliability
If the number of PRACH occasions is increased to handle multiple SS/PBCH block candidates, then random access reliability is improved, but system resource overhead increases
Solution Approach 1:
The patent introduces the QSSB parameter as a key variable that controls the mapping relationship between SS/PBCH block candidates and PRACH occasions. By adjusting QSSB, the system can dynamically control the number of PRACH occasions and their distribution. This parameter-based control allows the system to optimize the balance between random access reliability and resource overhead根据不同 scenarios, avoiding the need to always allocate maximum resources while ensuring sufficient reliability for each communication type.
Data Source
AI summary
A terminal apparatus includes: a receiver configured to receive an SS/PBCH block in an SS/PBCH block candidate; and a transmitter configured to transmit one random access preamble selected in a PRACH occasion. The terminal apparatus determines the PRACH occasion, based on a relationship between qSSB and the PRACH occasion. The qSSB is given by one of a remainder obtained by dividing tSSB by QSSB or a remainder obtained by dividing dSSB by QSSB. The tSSB is a timing index of the SS/PBCH block candidate. The dSSB indicates an index of a DMRS for a PBCH in the SS/PBCH block. The QSSB indicates a number included in an MIB in the PBCH.