Reference Signal Transmission for New Carrier Type Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE Release-11, carriers of new carrier types (NCT) reduce the density of cell-specific reference signals, making it impossible for user equipment (UE) to demodulate the physical broadcast channel (PBCH) directly, as cell-specific reference signals are not transmitted in all subframes, hindering UE access to NCT carriers.
Innovation Solution
A method where a base station transmits a reference signal with complex-valued modulation symbols to UE, allowing UE to determine the antenna ports and subcarriers for demodulating the broadcast channel, even in the absence of cell-specific reference signals, using predefined parameters to ensure accurate channel estimation and access to NCT carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If cell-specific reference signal density is decreased to reduce interference to other cells, then interference to other cells is reduced, but the ability to demodulate PBCH is lost
Solution Approach 1:
The patent introduces user-specific reference signals as an intermediary to replace cell-specific reference signals for PBCH demodulation. These user-specific reference signals are specifically configured for the target user equipment, enabling PBCH demodulation on NCT carriers without relying on cell-specific reference signals that would cause interference to other cells.
Solution Approach 2:
The patent changes the reference signal parameters by transitioning from cell-specific reference signals to user-specific reference signals. This parameter change includes modifying the signal structure, resource allocation, and association relationships to enable PBCH demodulation while reducing interference to other cells.
2Quantity of substance
If cell-specific reference signals are transmitted only in some normal downlink subframes, then resource usage is optimized, but PBCH cannot be transmitted in NCT carriers
Solution Approach 1:
User-specific reference signals serve as an intermediary mechanism that enables PBCH transmission on NCT carriers. These signals are specifically configured for the target user, allowing the system to transmit PBCH on NCT carriers without requiring cell-specific reference signals in every subframe, thus optimizing resource usage while maintaining adaptability.
Solution Approach 2:
The system performs preliminary configuration of user-specific reference signals before PBCH transmission. This preliminary action includes configuring the reference signal parameters, resource allocation, and association relationships, ensuring that the necessary reference signals are in place to support PBCH demodulation when needed.
3Ease of operation
If UE accesses NCT carriers through PBCH of another carrier, then access is possible, but direct access to NCT carrier is prevented
Solution Approach 1:
User-specific reference signals act as an intermediary that enables direct UE access to NCT carriers. By configuring these reference signals specifically for the target user on the NCT carrier, the system allows UE to directly receive and demodulate PBCH on the NCT carrier itself, eliminating the need to access through another carrier and simplifying the access procedure.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Embodiments of the present invention relate to the technical field of communications, and provide a method and device for transmitting a reference signal. The purpose is that a carrier of a new carrier type can transmit a broadcast channel, a UE can directly receive the broadcast channel from the carrier of the new carrier type and can be further accessed to the carrier of the new type. The method for transmitting a reference signal comprises: a base station determining an antenna port of a reference signal corresponding to a broadcast channel; the base station determining a complex valued modulation symbol of the reference signal according to a first parameter of the reference signal, wherein the first parameter of the reference signal is determined by the number of resource blocks occupied by the broadcast channel; and the base station transmitting the determined complex valued modulation symbol of the reference signal to a user terminal on the determined antenna port of the reference signal. The present invention can be used in an LTE wireless communication system.