Reverse Link Feedback Multiplexing Using Code Division Masks

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Solution Overview

Problem

In wireless communication systems, particularly those using CDMA protocols, there is a challenge in efficiently multiplexing reverse link feedback channels to support multiple forward link frequencies, leading to bandwidth limitations and increased interference, especially in high data rate transmissions.

Innovation Solution

The solution involves assigning reverse link frequencies to mobile stations and using code division multiplexing to combine multiple reverse link feedback channels on a single reverse link frequency, employing different long code masks for each forward link frequency to separate and transmit feedback information effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple reverse link feedback channels are assigned to support multiple forward link frequencies, then the system can support more forward link frequencies, but the reverse link bandwidth is consumed and interference increases

Engineering Contradiction:

Improvesupport for multiple forward link frequenciesVSAvoidinterference and bandwidth limitation

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines multiple reverse link feedback channels (ACK, NACK, DRC) onto a single reverse link frequency by using code division multiplexing with different long code masks for each feedback type, allowing multiple forward link frequencies to be supported without requiring separate reverse link frequencies for each

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the code mask parameter to differentiate between various feedback channels transmitted on the same reverse link frequency, using specific long code masks (e.g., 0xAA for ACK, 0x55 for NACK, 0xFF for DRC) to enable the receiver to distinguish and separate different feedback types

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If separate reverse link frequencies are used for each forward link frequency, then interference is reduced, but bandwidth utilization decreases

Engineering Contradiction:

Improveinterference reductionVSAvoidbandwidth utilization

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent merges multiple feedback channels that would traditionally require separate frequencies into a single reverse link frequency by utilizing code division multiplexing, thereby improving bandwidth utilization while maintaining the ability to distinguish different feedback types through unique code masks

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from frequency-domain separation to code-domain separation, moving the differentiation mechanism from the frequency dimension to the code dimension, allowing multiple channels to coexist on the same frequency without interference

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS8983480B2Multiplexing on the reverse link feedbacks for multiple forward link frequencies

Publication Date: 2015.03.17 QUALCOMM INC

AI summary

A method and apparatus for multiplexing reverse link feedback channels on a single reverse link frequency supporting multiple forward link frequencies for forward link channels is provided. The design includes assigning the reverse link frequency to a mobile station, assigning one or more of the forward link frequencies to the reverse link frequency, and code division multiplexing a plurality of the reverse link feedback channels on the reverse link frequency.