HARQ Entity Distinguishes New Transmissions in System Access
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Solution Overview
Problem
Wireless communication systems face challenges in providing hybrid automatic repeat/request (HARQ) functionality for system access communications, particularly due to the absence of new data indicators (NDIs) in transmissions between mobile devices and base stations.
Innovation Solution
A method and apparatus are introduced to facilitate HARQ support by determining whether a resource grant received in a system access response is a new transmission or retransmission based on the type of response, using a HARQ entity that processes communications and provides indications of new or retransmitted data, even in the absence of explicit NDIs, by considering the presence of a temporary or permanent device address.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ functionality is implemented for system access communications, then data transmission reliability is improved, but the complexity of the communication protocol increases due to the need to distinguish between new transmissions and retransmissions without explicit NDIs
Solution Approach 1:
The patent introduces an intermediary mechanism using the temporary address field as a mediator to indicate transmission type. Instead of relying on the traditional NDI indicator, the system uses the presence or absence of a temporary address in the MAC header to distinguish between new transmissions and retransmissions, enabling HARQ functionality without requiring additional explicit indicator bits.
Solution Approach 2:
The patent changes the interpretation of existing parameters in the MAC header. Specifically, it reuses the temporary address field (which may already be present in the header) to serve as an implicit NDI indicator. By changing how this existing parameter is interpreted based on its presence or state, the system achieves new transmission detection without adding new parameters.
2Adaptability or versatility
If the system uses temporary addresses for device identification in initial access, then access flexibility is improved, but the ability to reliably detect retransmissions deteriorates without additional indicator bits
Solution Approach 1:
The patent makes the temporary address field multi-functional. It serves both its traditional purpose of identifying devices during initial access and simultaneously acts as an implicit indicator for transmission type (new vs. retransmission). This universal usage allows the system to maintain access flexibility while enabling reliable retransmission detection through the same field.
Data Source
AI summary
Systems and methodologies are described that facilitate utilizing hybrid automatic repeat/request (HARQ) in system access communications. A HARQ entity is provided that manages a plurality of HARQ processes, which can typically use new data indicators (NDI) to determine when received data is a new transmission or retransmission. For resource grants, the HARQ entity can determine whether the communication is a new transmission or retransmission based on the type of message that contains the grant. In addition, an address comprised within the message, a previous use of the HARQ process, and/or the like can further be utilized to determine whether the message is a new transmission or retransmission. Once determined, the HARQ entity can provide the message to the appropriate HARQ process along with the indication of new transmission or retransmission.