Uplink Reference Signal Orthogonality in CoMP Wireless Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, the increasing demand for data throughput and the need to efficiently manage uplink/downlink data and control information within finite radio resources pose challenges, particularly in CoMP environments where multiple eNBs communicate with UEs using shared time-frequency resources.
Innovation Solution
A method for transmitting an uplink signal by a UE, involving the reception and generation of a Reference Signal (RS) using parameter sets that include a Virtual Cell Identifier (VCI) and sequence shift offsets, allowing for efficient RS transmission across multiple reception points, thereby optimizing resource usage and ensuring correct channel estimation and demodulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple eNBs communicate with UEs using the same time-frequency resources in CoMP, then data throughput is increased, but interference management and resource allocation complexity increases
Solution Approach 1:
The patent segments the reference signal resources by introducing different parameter sets (VCI, sequence shift offsets) for different reception points. This segmentation allows multiple eNBs to simultaneously use the same time-frequency resources while maintaining distinguishable reference signals, thus enabling CoMP operation without excessive interference
Solution Approach 2:
The patent changes parameters of the reference signal (Virtual Cell Identifier, sequence shift offset) to create orthogonal or near-orthogonal reference signals across different reception points. This parameter variation enables the system to support multiple eNBs in CoMP while managing interference through controlled parameter differentiation
2Productivity
If the number of UEs served by an eNB is increased, then system capacity is improved, but the amount of control information and radio resources required increases
Solution Approach 1:
The patent creates a universal reference signal structure that can serve multiple UEs and multiple reception points using the same basic framework. By defining parameter sets that can be reused across different UEs and eNBs, the system increases capacity without linearly increasing control information overhead
Solution Approach 2:
The patent uses parameter changes (VCI, sequence shift offset) to multiplex multiple UEs and reception points within the same resource framework. This allows the system to serve more UEs by varying reference signal parameters rather than allocating separate dedicated resources to each UE
3Measurement precision
If reference signals are transmitted across multiple reception points with different parameters, then channel estimation accuracy is improved, but signal generation and coordination complexity increases
Solution Approach 1:
The patent applies local quality by assigning specific parameter sets (VCI, sequence shift offset) to specific reception points. Each reception point uses locally optimized parameters tailored to its characteristics, improving channel estimation accuracy for that specific point while maintaining a unified overall structure
Solution Approach 2:
The patent performs preliminary action by pre-defining parameter sets for different reception points before actual communication occurs. This advance configuration simplifies real-time signal generation and coordination, as the parameters are already determined and ready for use
Data Source
AI summary
A method for receiving an uplink signal by a base station (BS) in a wireless communication system includes transmitting, to a user equipment (UE), a physical uplink shared channel demodulation reference signal (PUSCH DMRS) parameters including a first virtual cell identifier (VCI), transmitting, to the UE, a physical uplink control channel demodulation reference signal (PUCCH DMRS) parameters including a second VCI, and receiving, from the UE, the PUSCH DMRS or the PUCCH DMRS, wherein the first VCI for the PUSCH DMRS is determined from a first VCI range, the second VCI for the PUCCH DMRS is determined from a second VCI range, and wherein the first VCI range is wider than the second VCI range.