Non-staggered Pilot Tones for Reduced Channel Estimation Complexity
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Solution Overview
Problem
The use of staggered pilot tones in wireless communication systems increases the complexity of channel estimation for user equipment (UE), as pilot tones on the same tone location are transmitted every other symbol, rather than every symbol, leading to inefficiencies in interference estimation and channel estimation.
Innovation Solution
Implementing non-staggered pilot tones, where pilot tones are transmitted contiguously or scrambled with the same scrambling sequence on both symbols, allowing UE to perform channel estimation without needing to descramble the pilot tones first, thereby reducing estimation complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If staggered pilot tones are used to provide broader frequency coverage, then frequency coverage is improved, but channel estimation complexity increases
Solution Approach 1:
The patent inverts the traditional staggered pilot tone approach by using non-staggered pilot tones that are transmitted on the same tone locations across multiple symbols. This inversion simplifies channel estimation while maintaining frequency coverage through contigous allocation of resource blocks, resolving the contradiction between coverage and complexity
Solution Approach 2:
The patent changes the temporal parameter of pilot tone transmission from staggered (alternating symbols) to non-staggered (contiguous symbols). This parameter change allows UE to perform channel estimation without descrambling, reducing computational complexity while maintaining frequency coverage through contiguous resource block allocation
2Area of stationary object
If staggered pilot tones are transmitted every other symbol, then frequency coverage is broadened, but interference estimation complexity increases
Solution Approach 1:
The patent inverts the staggered transmission pattern by transmitting pilot tones on contiguous symbols at the same tone locations. This inversion enables simpler interference estimation since the pilot tones are not scrambled across different symbols, while frequency coverage is maintained through contiguous resource block allocation
Solution Approach 2:
The patent performs channel and interference estimation before descrambling the pilot tones. This preliminary action is made possible by the non-staggered transmission structure, reducing computational complexity while maintaining broad frequency coverage through contiguous resource allocation
Data Source
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AI summary
Methods, systems, and devices for wireless communication are described. A wireless communications system may support techniques for using non-staggered reference signals to increase the efficiency of the system and reduce the complexity of channel estimation. A base station may schedule a transmission to a user equipment (UE) including pilot tones mapped to a first symbol and a second symbol. In some cases, the pilot tones on the first and second symbols may be non-contiguous, and the base station may scramble the pilot tones on the first and second symbols according to the same scrambling sequence. In other cases, the pilot tones on the first and second symbols may be contiguous, and the pilot tones may be scrambled according to the same or different scrambling sequences. These techniques may result in reduced complexity for interference estimation and channel estimation at a UE.