Satellite Rate-Splitting With Multiple Set-Wise Common Streams

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Solution Overview

Problem

Conventional satellite communication systems face inefficiencies in allocating frequency spectrum due to interference between spot beams, leading to reduced maximum information rates and limited system capacity, especially in aggressive frequency reuse scenarios.

Innovation Solution

Implementing precoded rate-splitting with multiple set-wise common streams, grouping user locations with similar channel vectors into sets, and applying separate precoding for private and common streams to optimize power allocation and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If frequency spectrum is divided into bands and assigned to adjacent spot beams (frequency reuse), then interference between spot beams is reduced, but the maximum information rate supported by each spot beam is appreciably reduced

Engineering Contradiction:

Improveinterference between spot beamsVSAvoidmaximum information rate

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes the parameter of frequency allocation by transitioning from traditional frequency reuse (where adjacent beams use different frequencies) to aggressive frequency reuse (where adjacent beams use the same frequency). This parameter change enables full spectrum utilization while managing interference through advanced signal processing techniques like rate-splitting and common stream extraction.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If precoding is applied to suppress interference in spot beam coverage areas, then interference response is reduced, but desired signal response is also suppressed

Engineering Contradiction:

Improveinterference responseVSAvoiddesired signal response

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent extracts the common information component from the private streams and separates it into a common stream. This extracted common stream is then used to pre-compensate for interference, allowing the private streams to maintain higher power levels while still controlling interference through the decoded common information.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary decoding of the common stream at receivers before decoding private streams. This preliminary action allows receivers to remove the common stream component from the received signal, effectively pre-compensating for interference and improving the signal-to-interference ratio for private stream decoding.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If transmission power is reduced to lower interference levels, then interference noise in other spot beams is reduced, but desired signal levels are also reduced

Engineering Contradiction:

Improveinterference noiseVSAvoiddesired signal level

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent converts the harmful interference caused by common stream transmission into a beneficial signal. By intentionally designing the common stream to carry information that can be decoded and removed by receivers, the interference becomes a structured signal that aids in interference cancellation rather than random noise that degrades performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Use of energy by moving object

If a single common stream is used in rate-splitting, then power can be reallocated from private streams, but the information rate of the common stream must be limited by the most disadvantaged receiver

Engineering Contradiction:

Improvetransmission power allocationVSAvoidcommon stream information rate

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent segments the user population into different groups based on their channel conditions and interference characteristics. Different common streams can be targeted at different user groups, allowing each common stream to be optimized for its specific group rather than being constrained by the most disadvantaged receiver across all users. This segmentation enables higher overall system capacity.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20250317196A1Precoded rate-splitting with multiple set-wise common streams for aggressive frequency reuse in a satellite communication system

Publication Date: 2025.10.09 HUGHES NETWORK SYST

AI summary

Techniques are described for precoded rate-splitting with multiple set-wise common messages for frequency reuse in a multi-beam satellites. The satellite transmits private streams (PSs) to various user locations via spot beams. Embodiments identify various user groups as being in adjacent spot beam coverage areas and having high channel vector collinearity. For each user group, data from the corresponding PSs is multiplexed to a respective set-wise common stream (SCS). PS precoders are each computed based on an associated target user location, and SCS precoders are each computed based on an associated target user group. The satellite allocates transmit power and transmits the PSs and SCSs.