Interweaving Zero Symbol Rate Modulation Symbols for Wireless Resource Efficiency

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Solution Overview

Problem

Wireless communications systems face inefficiencies in utilizing air link resources for downlink traffic channel signaling due to variations in user data needs, leading to wasted resources and interference, particularly when high and low data rate users share the same air link resources.

Innovation Solution

The solution involves interweaving modulation symbols from two different coding/modulation streams, where one stream has a zero symbol rate and the other uses conventional modulation schemes like QPSK or QAM, allowing for efficient sharing of transmission resources by allocating non-zero symbols from the zero symbol rate stream at higher power and filtering out lower power symbols as noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If superposition signaling is implemented to increase the number of active users, then user capacity is improved, but interference problems occur

Engineering Contradiction:

Improveuser capacityVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The traffic channel segment is divided into multiple sub-segments, each capable of carrying independent data streams. This segmentation allows different users to be assigned to different sub-segments, reducing mutual interference while maintaining high user capacity. The base station can selectively activate sub-segments based on user requirements and channel conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sub-segments within the traffic channel segment are allocated with different properties (e.g., different modulation schemes, coding rates, or power levels) tailored to specific user requirements. This local differentiation allows high data rate users to utilize certain sub-segments while low data rate users use others, minimizing cross-user interference.

Inventive Principle:

Principle #3Local quality

2Device complexity

If fixed number of MTUs are used in each downlink traffic channel segment for convenience of assignment, then assignment complexity is reduced, but air link resource efficiency deteriorates

Engineering Contradiction:

Improveassignment complexityVSAvoidair link resource efficiency

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the number of Minimum Transmission Units (MTUs) allocated to each user within the traffic channel segment based on real-time channel conditions, user data rate requirements, and traffic load. This dynamic allocation allows the system to optimize air link resource efficiency while maintaining manageable assignment complexity through automated resource management.

Inventive Principle:

Principle #15Dynamics

3Productivity

If downlink traffic channel segment size is increased to serve users with large data needs, then data throughput is improved, but resource waste occurs for users with small data needs

Engineering Contradiction:

Improvedata throughputVSAvoidresource waste

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The traffic channel segment is divided into multiple sub-segments that can be independently allocated to different users. Users with large data needs can be assigned multiple sub-segments, while users with small data needs receive only the necessary number of sub-segments. This granular allocation eliminates resource waste by matching segment size to actual user requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the allocation parameters (number of sub-segments, MTUs per sub-segment, modulation order, coding rate) based on user-specific requirements. This parameter adaptation allows the system to optimize resource utilization for each user, preventing both under-provisioning and over-provisioning of air link resources.

Inventive Principle:

Principle #35Parameter changes

4Stability of the object's composition

If padding is used to complete coding blocks, then coding structure integrity is maintained, but air link resources are wasted

Engineering Contradiction:

Improvecoding structure integrityVSAvoidair link resources

Core Design Contradiction:

Stability of the object's compositionVSLoss of substance

Solution Approach 1:

By segmenting the traffic channel into multiple sub-segments, the system can allocate complete coding blocks only to the extent necessary for each user's data payload. Remaining capacity in partially filled sub-segments can be reassigned to other users or left unused rather than being wasted through padding, thus maintaining coding integrity where needed while eliminating unnecessary resource consumption.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS7706456B2Methods and apparatus for combining and/or transmitting multiple symbol streams

Publication Date: 2010.04.27 QUALCOMM INC

AI summary

A stream of modulation symbols from a zero symbol rate (ZSR) coding/modulation module and a stream of modulation symbols from another type of coding/modulation module are input into an interweaver module. The interweaver module mixes the two input streams when assigning modulation symbols to be communicated in a segment. If a ZSR modulation symbol is non-zero, the ZSR modulation symbol is allocated a transmission position. If the ZSR modulation symbol is a zero modulation symbol, the modulation symbol from the other coding/modulation module is allocated the transmission position. The non-zero modulation symbols from the ZSR module are higher in power than the non-zero modulation symbols from the other module, thus facilitating detection and recovery.