DMRS Generation for E-PDCCH Demodulation Without SCID
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Solution Overview
Problem
In LTE communications systems, user equipment (UE) cannot demodulate Extended Physical Downlink Control Channels (E-PDCCH) due to lack of knowledge about the Scrambling Identifier (SCID) required for generating Demodulation Reference Signals (DMRS), preventing successful demodulation of E-PDCCH.
Innovation Solution
The base station generates and sends DMRS to the UE using available information such as cell ID and Radio Network Temporary Identifier (RNTI) before transmitting the E-PDCCH, allowing the UE to generate the DMRS and demodulate the E-PDCCH without relying on the SCID.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the SCID is used to generate DMRS for E-PDCCH demodulation, then the DMRS can be generated according to a specific identifier, but the UE cannot know the SCID beforehand and therefore cannot generate the DMRS
Solution Approach 1:
The base station generates and transmits the DMRS to the UE before transmitting the E-PDCCH. This preliminary action allows the UE to obtain the DMRS in advance, eliminating the need for the UE to know the SCID beforehand, thus resolving the information availability problem while ensuring reliable DMRS generation
Solution Approach 2:
The base station acts as an intermediary that generates the DMRS using the SCID and transmits it to the UE. This intermediary action allows the UE to obtain the DMRS without needing to know the SCID, as the base station performs the scrambling operation using the SCID as a mediator
2Productivity
If the downlink control channel region uses only three OFDM symbols, then the structure remains simple, but the capacity is insufficient to meet the requirements of CoMP and MU-MIMO scheduling
Solution Approach 1:
The E-PDCCH is introduced to utilize resources in the downlink data channel region, adding a new dimension for control channel transmission. This allows the system to increase user scheduling capacity by using both the traditional PDCCH region and the new E-PDCCH region without significantly increasing the complexity of the existing PDCCH structure
3Adaptability or versatility
If the E-PDCCH shares time-and-frequency resources with PDSCH, then resource utilization improves, but the UE cannot demodulate E-PDCCH without knowing the SCID
Solution Approach 1:
The base station generates and transmits the DMRS to the UE before transmitting the E-PDCCH. This preliminary action ensures that the UE has the necessary reference signal for demodulation before receiving the control channel, making the resource sharing between E-PDCCH and PDSCH feasible without complicating the demodulation process
Data Source
Figure 1~3A
Figure 3B~4
Figure 5~6
AI summary
The present invention provides a demodulation reference signal processing method, a base station and a user equipment. A processing method includes: generating, by a base station, a DMRS corresponding to an E-PDCCH by using information that is available before a UE receives the E-PDCCH sent by the base station; and mapping, by the base station, the DMRS onto a time-and-frequency resource corresponding to a downlink control channel region and used for transmitting a reference signal, and sending the DMRS to the UE. In the technical solutions of the present invention, the base station and the UE no longer use an SCID for generating the DMRS, which solves the problem that the UE cannot obtain the SCID before receiving the E-PDCCH and cannot generate the DMRS, and further, cannot demodulate the E-PDCCH, and enables demodulation of the E-PDCCH.