Reference Signal Transmission in New Carrier Type
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Solution Overview
Problem
In wireless communication systems, especially in LTE networks, the existing reference signal transmission methods lead to increased overhead and interference, particularly in heterogeneous networks, which affects the performance and energy efficiency of small cells and macro cells.
Innovation Solution
A method for transmitting a reference signal that includes transmitting secondary synchronization signals (SSS) and primary synchronization signals (PSS) in specific resource blocks within a subframe, along with a reference signal based on a cell identifier, optimized for small cells and macro cells, using a new carrier type (NCT) that reduces overhead and interference by varying the structure of the transmitted reference signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cell-specific reference signals (CRS) are transmitted in all subframes, then coverage and reliability are improved, but overhead and energy consumption increase
Solution Approach 1:
The patent applies periodic action by transmitting cell-specific reference signals (CRS) only in specific periodic subframes (e.g., every 5th or 10th subframe) rather than in every subframe. This periodic transmission pattern reduces the quantity of reference signals while maintaining sufficient coverage and reliability for user equipment synchronization and channel estimation.
Solution Approach 2:
The patent extracts and removes CRS transmission from subframes where it is not strictly necessary, keeping it only in critical subframes for synchronization and channel estimation. This extraction approach reduces overall reference signal overhead while preserving essential coverage functionality.
2Reliability
If cell-specific reference signals (CRS) are transmitted in all subframes, then coverage and reliability are improved, but energy consumption increases
Solution Approach 1:
The base station implements periodic action by activating CRS transmission only in specific periodic subframes rather than continuously in all subframes. This periodic operation significantly reduces base station energy consumption while maintaining adequate coverage reliability through strategic reference signal placement in critical subframes.
Solution Approach 2:
The patent extracts CRS transmission from non-essential subframes, removing unnecessary energy-consuming operations while preserving coverage reliability in subframes where CRS transmission is critical for user equipment synchronization and channel estimation.
3Adaptability or versatility
If reference signals are transmitted with legacy structure, then backward compatibility is maintained, but interference in heterogeneous networks increases
Solution Approach 1:
The patent applies local quality by making the reference signal structure configurable and adaptable to different network conditions. The system can selectively apply legacy CRS structure in certain subframes for backward compatibility while using reduced or alternative reference signal structures in other subframes to minimize interference in heterogeneous networks, allowing local optimization of signal properties.
Solution Approach 2:
The patent implements dynamics by enabling flexible switching between legacy reference signal structures and reduced overhead structures based on network conditions and cell type. This dynamic adaptability allows the system to maintain backward compatibility when needed while reducing interference in heterogeneous network scenarios through configurable reference signal transmission patterns.
4Measurement precision
If cell-specific reference signals (CRS) are transmitted in every subframe, then channel estimation accuracy is improved, but overhead increases
Solution Approach 1:
The patent applies periodic action by transmitting CRS only in specific periodic subframes rather than every subframe. This approach maintains sufficient channel estimation accuracy by providing regular reference signal updates at periodic intervals while significantly reducing reference signal overhead through the selective transmission pattern.
Data Source
AI summary
Disclosed are a method and an apparatus for transmitting a reference signal. The method for transmitting the reference signal comprises the step of: transmitting a secondary synchronization signal (SSS) and a primary synchronization signal (PSS) from a subframe including an N (natural number wherein N>1) number of resource blocks (RB) and a plurality of orthogonal frequency division multiplexing (OFDM) symbols; and transmitting from the subframe the reference signal which is generated on the basis of a cell identifier, wherein the reference signal can be transmitted from an M (natural number wherein K<=M<N) number of RBs which includes a K number of RBs in the OFDM symbols that remain after excluding the OFDM symbols from which the SSS and the PSS are transmitted. As a result, demodulation capability of a terminal can be increased.