Cross-Carrier Scheduling Data Start Indicator
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Solution Overview
Problem
In wireless communication systems supporting multiple carriers, existing technologies face challenges in efficiently receiving downlink signals due to errors in carrier indicator fields, leading to HARQ buffer corruption and incorrect decoding of data channels.
Innovation Solution
A method and apparatus for a user equipment (UE) to receive a downlink signal by decoding a data channel corresponding to a control channel transmitted in a specific subframe using parameters from a different carrier, with information about the start OFDM symbol of data channels signaled via a higher layer, utilizing a carrier indicator field, data start indicator, or control format indicator to ensure accurate decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cross-carrier scheduling is used to transmit control channels and data channels on different carriers, then carrier aggregation efficiency is improved, but errors in carrier indicator fields cause HARQ buffer corruption and incorrect decoding
Solution Approach 1:
The patent introduces a data start indicator as an intermediary element between the carrier indicator field and the data channel decoding process. This indicator explicitly signals the start OFDM symbol of the data channel, mediating the potential mismatch between carrier indicator field information and actual data channel location, thereby preventing HARQ buffer corruption while maintaining cross-carrier scheduling efficiency
Solution Approach 2:
The patent applies preliminary action by signaling the data start indicator before the data channel transmission begins. This advance indication allows the UE to prepare the HARQ buffer in advance and correctly position itself for receiving the data channel on the second carrier, preventing decoding errors before they occur
2Device complexity
If the start OFDM symbol of data channels is not explicitly signaled, then device complexity is reduced, but decoding accuracy deteriorates due to potential mismatches in carrier indicator field
Solution Approach 1:
The patent changes the parameter used for indicating data channel location from relying solely on the carrier indicator field to using an explicit data start indicator. This parameter change provides more precise and reliable information about the data channel start position, improving decoding accuracy without significantly increasing device complexity
Data Source
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AI summary
The present invention relates to a method for receiving a downlink signal at a terminal in a wireless communication system. In particular, the method comprises: receiving a control channel to be transmitted to a specific subframe via a first carrier; and decoding a data channel corresponding to the control channel to be transmitted to the specific subframe via a second carrier, using at least one parameter included in the control channel, wherein information on the orthogonal frequency division multiplexing (OFDM) start symbol of data channels that are transmitted via each of at least one carrier allocated to the terminal is signaled through an upper layer.