Single Downlink Multi-Antenna Mode for Random Access Signaling

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Solution Overview

Problem

In wireless cellular systems, there is a need for users to know which multi-antenna transmission mode is employed during Random Access procedures, as existing systems lack a reliable method for the eNodeB to select the appropriate mode due to lack of information about the UE's perception of the radio channel, especially during initial access and contention-based random access.

Innovation Solution

Implementing a method where the first node in the system uses a single downlink multi-antenna transmission mode during Random Access procedures, which can be standardized, overridden, or autonomously chosen by the node, and signaled to UEs through a broadcast channel, ensuring all UEs in a cell know the mode to expect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple downlink multi-antenna transmission modes are supported by the eNodeB, then the system's adaptability and transmission efficiency are improved, but the complexity of selecting and signaling the appropriate mode during Random Access procedures increases

Engineering Contradiction:
Improvemulti-antenna transmission mode supportVSAvoidmode selection and signaling complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by configuring different downlink multi-antenna transmission modes for different procedural contexts. Specifically, a first mode is configured for Random Access procedures while a second mode is configured for other downlink transmissions. This allows the system to optimize performance for each specific scenario without requiring complex dynamic selection during Random Access, as the mode is predetermined and separately configured for each context.

Inventive Principle:
Principle #3Local quality

2Reliability

If the eNodeB dynamically selects multi-antenna transmission modes based on channel conditions, then transmission reliability is improved, but the ability to ensure consistent mode usage during Random Access procedures deteriorates due to lack of UE channel perception information

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidUE perception of radio channel information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by configuring the downlink multi-antenna transmission mode for Random Access procedures in advance, before the actual Random Access procedure begins. The eNodeB separately configures a first downlink multi-antenna transmission mode specifically for Random Access procedures, independent of the mode used for other transmissions. This preliminary configuration ensures that both eNodeB and UE know which mode to use during Random Access, eliminating the information loss problem while maintaining dynamic mode selection capabilities for other scenarios.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3145096B1Selection of transmit mode during a random access procedure
Publication Date: 2018.08.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3145096B1 patent drawingFigure 1
  • EP3145096B1 patent drawingFigure 2
  • EP3145096B1 patent drawingFigure 3

AI summary

The invention discloses a method (400) for use in a first node (110) in a wireless access communication system (100). According to the method, the first node controls (405) traffic to and from users, UEs (120), within a certain area in the system, a cell, and the first node is equipped (410) with a plurality of transmit antennas (111,113). The first node can employ (415) a variety of multi antenna transmit modes for down link transmissions, i.e. transmissions to the UEs, and the first node can carry (420) out a so called Random Access (RA) procedure with UEs which do not have a dedicated up link resource, i.e. a resource to the eNodeB. According to the method, one and the same down link multi antenna transmit mode is used by the first node during the RA procedure.