Control Channel Cyclic Delay Diversity With UE-Selected CDD Range
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Solution Overview
Problem
Existing wireless communication systems face challenges in implementing cyclic delay diversity (CDD) schemes that provide robustness and redundancy while minimizing signaling overhead, particularly in scenarios where optimal CDD values depend on changing channel conditions.
Innovation Solution
A network entity transmits a range of CDD parameter values to a UE, allowing the UE to select an appropriate CDD value based on measurements or configurations, thereby applying a cyclic delay to control channels and reducing overhead by signaling a range of values rather than fixed CDD values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed CDD values are used in control channels, then implementation is simple, but diversity gain is limited and cannot adapt to changing channel conditions
Solution Approach 1:
The patent applies dynamics by transitioning from fixed CDD values to dynamic CDD values that adapt to changing channel conditions. The network entity determines CDD values based on current channel state information, and these values can be updated over time to match varying propagation conditions, thereby improving adaptability while maintaining manageable complexity through structured determination methods.
Solution Approach 2:
The patent implements parameter changes by modifying the CDD parameter values based on channel conditions. Instead of using static CDD values, the system adjusts these parameters dynamically according to measured channel characteristics such as delay spread and Doppler frequency, allowing the control channel to adapt to different propagation environments while the network entity manages the parameter selection to control signaling overhead.
2Reliability
If CDD parameter values are signaled dynamically to adapt to channel conditions, then diversity gain is improved, but signaling overhead increases
Solution Approach 1:
The patent applies self-service by enabling the UE to autonomously determine appropriate CDD values based on channel measurements and network configurations. The UE uses received reference signals to estimate channel conditions and selects CDD parameters from configured sets without requiring explicit dynamic signaling from the network for each change, thereby improving reception quality while minimizing signaling overhead.
Solution Approach 2:
The patent implements preliminary action by having the network entity pre-configure multiple CDD parameter sets and indicate the applicable set to the UE. This allows the UE to quickly adapt to channel changes by selecting from pre-prepared options rather than waiting for dynamic signaling, improving reliability while reducing the frequency and overhead of network signaling.
3Ease of operation
If transparent CDD schemes are used, then UE implementation is simplified, but the UE cannot accurately compensate for cyclic delays
Solution Approach 1:
The patent introduces an intermediary approach where the network entity provides reference signals and configuration information that enable the UE to perform accurate CDD compensation. The reference signals serve as intermediaries that carry channel state information, allowing the UE to estimate channel conditions and determine appropriate CDD values without the network explicitly signaling each CDD parameter, thus balancing implementation ease with compensation accuracy.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A network entity may indicate a range of values for a cyclic delay diversity (CDD) parameter associated with a channel to a UE. The UE may select a CDD value from the range of values based on one or more measurements, a configuration, or both, associated with the channel. The network entity may apply a cyclic to the channel according to a CDD value from the range of values, and may transmit, according to the applied cyclic delay, signaling to the UE via the channel. In some cases, the UE may receive the second control signaling according to the CDD value selected by the UE. The network entity may indicate the range of values via one or more techniques, and the range of values may be associated with a set of channel conditions, control resources, or both.