SDMA Uplink Resource Allocation via Distributed Tone Selection

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently scheduling simultaneous uplink transmissions from multiple wireless nodes, particularly in SDMA systems, where synchronization and resource allocation can be complex and inefficient, leading to potential interference and reduced throughput.

Innovation Solution

The method involves using an OFDMA transmission scheme to request and allocate uplink resources, with a request-to-send message (RTS-MA) and acknowledgement (ACK) mechanism that allows wireless nodes to synchronize and allocate spatial streams and tones, reducing the scheduling burden on the access point and improving resource efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional scheduling methods are used for uplink transmissions in SDMA systems, then the access point can manage resource allocation, but the scheduling complexity and interference management become increasingly difficult as the number of wireless nodes increases

Engineering Contradiction:

Improvesystem throughputVSAvoidscheduling complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the uplink transmission process into distinct phases: wireless nodes independently select and transmit on available tones without centralized scheduling, dividing the complex scheduling problem into simpler individual node decisions. This reduces access point scheduling complexity while maintaining system throughput through distributed resource selection.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multiple wireless nodes transmit simultaneously in SDMA systems, then data throughput increases, but interference management and synchronization become more challenging

Engineering Contradiction:

Improvedata throughputVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent allows wireless nodes to transmit on a subset of available tones simultaneously rather than requiring complete frequency separation. By permitting partial overlap in tone usage with distributed selection, the system achieves higher throughput while managing interference through the statistical distribution of tone choices across multiple nodes.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If centralized resource allocation is implemented at the access point, then resource distribution can be optimized, but the signaling overhead and scheduling latency increase

Engineering Contradiction:

Improveresource efficiencyVSAvoidscheduling latency

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent implements preliminary distributed tone selection at wireless nodes before transmission, eliminating the need for real-time centralized allocation decisions. Nodes independently choose available tones in advance, reducing scheduling latency while maintaining resource efficiency through the preliminary distributed resource selection process.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8532038B2Methods and apparatus for frame exchange for SDMA uplink data

Publication Date: 2013.09.10 QUALCOMM INC

AI summary

Certain embodiments provide a method for scheduling simultaneous transmissions of data from multiple wireless nodes in a wireless communications system.