LTE-NR Random Access PDCCH Order UL Carrier Selection
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently transmitting and receiving signals based on LTE and NR, particularly in coexistence scenarios, due to ambiguity in UL signal transmission between LTE and NR bands, leading to difficulties in determining the correct transmission band and potential interference.
Innovation Solution
The proposed solution involves methods for performing a random access procedure in a 3GPP-based wireless communication system, where NR UL signals are scheduled on the LTE band, with specific timing and frequency positions indicated through control channels or higher-layer signaling, allowing for separate configuration of UL timing numerology and reference signal structures to ensure orthogonal transmission and beam separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NR UL signals are scheduled on LTE band, then resource utilization is improved, but ambiguity in transmission band increases
Solution Approach 1:
The patent introduces control channels (PDCCH, EPDCCH) and higher-layer signaling as intermediary mechanisms to carry scheduling information for NR UL signals. These intermediaries explicitly indicate the LTE band as the transmission carrier, resolving the ambiguity between LTE and NR bands while enabling efficient resource utilization through cross-carrier scheduling.
2Reliability
If UL timing numerology is configured separately, then transmission reliability is improved, but system complexity increases
Solution Approach 1:
The patent segments the UL timing configuration into separate parameters: a first timing parameter for NR UL signals and a second timing parameter for LTE UL signals. This segmentation allows independent optimization of timing numerologies for each technology while managing complexity through structured parameter separation in the configuration framework.
Solution Approach 2:
The patent applies parameter changes by configuring different timing numerologies (first and second timing parameters) for NR and LTE UL signals respectively. This enables adaptation of timing characteristics to each technology's requirements, improving reliability through optimized timing while maintaining manageable complexity through parameterized configuration.
3Reliability
If reference signal structures are differentiated, then signal orthogonality is improved, but configuration complexity increases
Solution Approach 1:
The patent applies local quality by configuring different reference signal structures for NR and LTE UL signals. Specifically, it distinguishes between first reference signals (for NR) and second reference signals (for LTE), with different structures optimized for each technology. This ensures signal orthogonality and reduces interference while managing complexity through localized differentiation.
Data Source
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AI summary
A method for performing a random access procedure by a device in a 3GPP-based wireless communication system is proposed, which comprises: receiving, downlink control information, DCI, through a physical downlink control channel, PDCCH, on a first downlink, DL, carrier of a serving cell configured in the device; and transmitting a random access preamble based on that the DCI being a PDCCH order which initiates a random access procedure; wherein the serving cell configured in the device includes the first DL carrier, a first uplink, UL, carrier and a second UL carrier, which have a same physical cell identifier, the second UL carrier is a supplementary uplink, SUL, carrier of the 3GPP-based wireless communication system, and an UL carrier for transmitting the random access preamble is determined between the first UL carrier and the SUL carrier, based on UL carrier indication information included in the DCI.