DMRS Port Multiplexing With Extended OCC in CDM Groups

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Solution Overview

Problem

Existing communication networks face challenges in increasing the number of DMRS ports without increasing signaling overhead, particularly in multi-user MIMO scenarios, which limits the capacity and efficiency of data transmission.

Innovation Solution

Employing frequency domain orthogonal cover codes (FD-OCC) of length three or six, combined with time domain orthogonal cover codes (TD-OCC) of length two or longer, to increase the number of DMRS ports within a physical resource block (PRB), allowing for more efficient DMRS configurations without additional overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of DMRS ports is increased to support more users in MU-MIMO, then the data transmission capacity is improved, but the signaling overhead increases

Engineering Contradiction:

Improvedata transmission capacityVSAvoidsignaling overhead

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent extends OCC sequences from traditional length-2 to length-3 or length-6 in the frequency domain, adding dimensional capacity to the DMRS port multiplexing scheme. This allows 6 or 12 DMRS ports per CDM group respectively, enabling support for up to 24 DMRS ports per PRB without requiring additional signaling resources.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the OCC sequence length parameter from conventional values (2) to extended values (3 or 6), fundamentally altering the multiplexing capacity. This parameter change enables more DMRS ports to be accommodated within the same resource block structure, increasing system capacity without proportional increases in overhead.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If frequency domain orthogonal cover codes of length three or six are employed, then the number of DMRS ports per PRB is increased, but the processing complexity increases

Engineering Contradiction:

Improvenumber of DMRS portsVSAvoidprocessing complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the frequency domain resources by assigning different OCC sequence lengths (3 or 6) to different CDM groups, allowing systematic organization of DMRS ports. This segmentation enables structured processing where each CDM group can be handled independently with its specific OCC length, managing complexity through modular organization.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12587323B2Multiple demodulation reference signal (DMRS) ports in a code division multiplexing (CDM) group

Publication Date: 2026.03.24 APPLE INC

AI summary

The present application relates to devices and components including apparatus, systems, and methods that support multiple demodulation reference signal (DMRS) ports per code division multiplexing (CDM) group. In an example, a frequency domain orthogonal cover code (FD-OCC) of length three or six is used, thereby allowing at least six DMRS ports for DMRS configuration type 1 with a single symbol DMRS, at least twelve DMRS ports for DMRS configuration type 1 with a double symbol DMRS, at least nine DMRS ports for DMRS configuration type 2 with a single symbol DMRS, and at least eighteen DMRS ports for DMRS configuration type 2 with a double symbol DMRS.