Unlicensed Channel Signaling for Subframe Validity
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently determining the end of a downlink transmission burst in unlicensed channels, leading to potential delays and reduced reliability in data reception, as they often require waiting for the next subframe to validate subframe validity.
Innovation Solution
The method involves signaling the number of OFDM symbols in each subframe, using reserved values to indicate end subframes, allowing user equipment (UE) to determine the validity of the next subframe without waiting for OFDM symbol #0, thereby improving reliability and reducing computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system waits for OFDM symbol #0 at the next subframe to determine subframe validity, then the determination is reliable, but the delay increases and productivity decreases
Solution Approach 1:
The patent applies preliminary action by embedding an end indicator in the current subframe that allows the UE to determine subframe validity in advance, without waiting for the next subframe's OFDM symbol #0. The end indicator is prepared and transmitted beforehand, enabling the UE to proactively identify the end subframe and stop monitoring, thus eliminating the waiting delay while maintaining reliable determination.
2Reliability
If the system monitors every subframe to ensure reliable data reception, then reception reliability is improved, but device complexity and energy consumption increase
Solution Approach 1:
The patent extracts the end indicator from the downlink transmission and places it in a specific field (such as the most significant bits of resource allocation or a dedicated field) that the UE can efficiently decode. This extraction allows the UE to identify the end subframe through a simple check of the indicator rather than complex monitoring of entire subframes, reducing device complexity while maintaining reliable reception.
Solution Approach 2:
The end indicator enables the UE to self-determine the end subframe without requiring continuous network signaling or complex base station coordination. The UE autonomously decodes the indicator from the received downlink data and independently decides when to stop monitoring, reducing both device complexity and energy consumption while ensuring reliable reception.
3Reliability
If the system uses explicit signaling for each subframe to indicate validity, then reliability is improved, but signaling overhead and device complexity increase
Solution Approach 1:
The patent makes the end indicator multi-functional by embedding it within existing downlink data structures such as resource allocation fields or transport block headers. This single indicator serves multiple purposes: it indicates the end subframe, can be decoded using existing UE functionality, and integrates with current signaling frameworks. This universal approach improves reliability without requiring separate dedicated signaling mechanisms, thereby avoiding increased device complexity.
Data Source
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AI summary
Methods and apparatuses for implementing reference signal transmissions in a wireless communication system. According to one method, the UE receives a downlink transmission burst from a base station in a first unlicensed channel (1305). The UE also receives an information in a second channel, wherein the information defines whether a subframe is an end subframe of the downlink transmission burst in the first unlicensed channel (1310). The UE determines whether or not to receive a control message, data, or a reference signal from a next frame in the first unlicensed channel (1315). The UE receives the control message, data, or a reference signal from the next frame in the first unlicensed channel if the information indicates that the subframe is not the end subframe of the downlink transmission burst (1320). Alternatively, the UE refuses to receive the control message, data, or the reference signal from the next frame in the first unlicensed channel if the information indicates that the subframe is the end subframe of the downlink transmission burst.