Asymmetric FDD Bandwidth Allocation for Spectrum Efficiency

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Solution Overview

Problem

Conventional FDD systems are not capable of accommodating the asymmetrical nature of downlink and uplink traffic, leading to inefficient spectrum utilization, especially in data communications where downlink traffic requires more resources.

Innovation Solution

An FDD system with flexible and adjustable channel bandwidths for uplink and downlink, allowing different sizes to be allocated based on traffic demands, enabling better spectrum utilization and accommodating asymmetrical traffic patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional FDD systems use fixed equal bandwidth allocation for uplink and downlink, then spectrum allocation is simple and symmetric, but spectrum utilization efficiency deteriorates due to inability to accommodate asymmetrical traffic patterns

Engineering Contradiction:

Improvespectrum utilization efficiencyVSAvoidbandwidth allocation complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic bandwidth allocation in FDD systems where the bandwidth for uplink and downlink can be adjusted independently based on traffic conditions. The system allows flexible configuration of bandwidth parameters to match actual traffic demands, transforming the static fixed bandwidth allocation into a dynamic adaptive mechanism that optimizes spectrum utilization efficiency.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the bandwidth parameter allocation from fixed equal values to variable asymmetric values. By allowing independent adjustment of uplink and downlink bandwidth parameters, the system can optimize spectrum utilization according to traffic patterns while maintaining FDD operational simplicity through standardized configuration procedures.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If FDD systems allocate equal bandwidth to uplink and downlink, then configuration is simple, but resource wastage increases due to asymmetrical traffic demands

Engineering Contradiction:

Improveresource wastageVSAvoidbandwidth configuration ease

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The patent applies different bandwidth quality levels to different directions (uplink and downlink) based on their specific traffic requirements. Instead of uniform bandwidth allocation, the system allows each direction to have optimized bandwidth configuration, reducing resource wastage by matching bandwidth allocation to actual local traffic needs in each direction.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system enables dynamic adjustment of bandwidth allocation to match varying traffic conditions, allowing the network to adapt bandwidth resources locally to each direction's needs. This dynamic capability reduces resource wastage during low-traffic periods while maintaining adequate capacity during high-traffic periods.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If TDD systems use flexible time allocation between uplink and downlink, then asymmetrical traffic is accommodated well, but stringent synchronization requirements between neighboring cells increase system complexity

Engineering Contradiction:

Improveasymmetrical traffic accommodationVSAvoidsynchronization complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of using time-division multiplexing with flexible time allocation like TDD, the patent applies frequency-division multiplexing with flexible frequency allocation. By inverting the approach from time-based to frequency-based separation, the system achieves asymmetrical traffic accommodation without the stringent synchronization requirements that plague TDD neighboring cell coordination.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent moves the flexibility from the time dimension (TDD) to the frequency dimension (FDD). By allocating different bandwidths in the frequency domain rather than different time slots, the system achieves asymmetrical traffic support while avoiding the synchronization complexity inherent in time-based approaches.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Productivity

If FDD systems use fixed bandwidth allocation, then system operation is simple, but data communication efficiency deteriorates due to inability to adapt to varying traffic demands

Engineering Contradiction:

Improvedata communication efficiencyVSAvoidbandwidth adjustment capability

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent transforms fixed bandwidth allocation into a dynamic system where bandwidth parameters can be adjusted based on traffic conditions. This dynamic capability allows the system to optimize data communication efficiency by adapting bandwidth resources to match actual traffic demands while maintaining manageable operational complexity through standardized adjustment procedures.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8325670B2Method, apparatus and computer-readable medium for asymmetric frequency division duplexing operation

Publication Date: 2012.12.04 NEXTEL COMMUNICATIONS INC

AI summary

A method, apparatus, and computer-readable medium for performing asymmetric frequency division duplexing (FDD) are provided. The method includes allocating a first bandwidth for an uplink portion of an FDD data transmission; and allocating a second bandwidth for a downlink portion of the FDD data transmission; wherein the first bandwidth and the second bandwidth have different sizes.