Channel Quality Indicator Piggybacking in Uplink Data
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Solution Overview
Problem
In mobile communication systems, requesting and reporting channel quality information from multiple subscriber stations can exhaust downlink resources and lead to delays in uplink resource allocation, causing subscriber stations to fail in transmitting timely response messages, which affects adaptive processing in mobile environments.
Innovation Solution
The method involves allocating uplink radio resources with a channel quality information indicator, allowing subscriber stations to piggyback channel quality information onto uplink data, reducing the need for additional messages and ensuring timely reporting by integrating CQI requests within existing data transmission, thereby optimizing resource usage and reducing delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station requests channel quality information from multiple subscriber stations individually using separate messages, then the channel quality information can be collected from each subscriber station, but the downlink resources are exhausted and overhead messages are increased
Solution Approach 1:
The patent combines multiple individual CQI request messages into a single groupcast message that can be received by multiple subscriber stations simultaneously. This merging approach reduces the number of downlink transmissions required while still collecting CQI information from multiple subscriber stations, thereby conserving downlink resources.
Solution Approach 2:
The groupcast message serves multiple functions: it requests CQI information from multiple subscriber stations, allocates uplink resources for their responses, and can include configuration parameters for the CQI reporting. This multi-functional approach reduces the need for separate messages and optimizes resource usage.
2Productivity
If the base station transmits CQI request messages using existing AMC levels determined from outdated channel quality information, then the transmission can proceed with current resource allocation, but some subscriber stations may fail to receive the messages due to degraded channel conditions
Solution Approach 1:
The base station performs preliminary channel quality assessment using the most recent CQI reports before transmitting the groupcast request message. Based on this preliminary assessment, it selects an appropriate AMC level that ensures reliable reception even in degraded conditions, rather than using outdated AMC levels that may have been determined from older channel quality information.
3Reliability
If subscriber stations transmit response messages individually using separate uplink resources, then each station can report its channel quality information, but heavy delays occur due to lack of guaranteed uplink resource allocation
Solution Approach 1:
The base station performs preliminary uplink resource allocation when transmitting the groupcast CQI request message. It includes uplink resource allocation information in the message that guarantees resources for the response transmissions. This preliminary allocation eliminates the need for separate resource request and allocation procedures, ensuring timely response message transmission.
Solution Approach 2:
Multiple subscriber stations are allocated uplink resources in a coordinated manner through the groupcast mechanism. The base station can allocate resources for multiple responses simultaneously or in a structured sequence, reducing the overall time required compared to individual ad-hoc resource allocations.
4Loss of information
If additional message formats are used for CQI reporting, then channel quality information can be accurately reported, but message overheads are increased
Solution Approach 1:
The patent combines the CQI report message with uplink data transmission using piggybacking. The CQI information is embedded in the uplink data message rather than being sent in a separate dedicated CQI message. This merging reduces message overhead while maintaining accurate CQI reporting capability.
Data Source
AI summary
The subscriber station of claim 15, wherein the uplink data includes data to be transmitted, and a header having information on the data and the subscriber, and the uplink data generator adds the subheader includDisclosed is a method and device for requesting and reporting channel quality information in a mobile communication system. An uplink radio resource for a subscriber station having data to transmit is allocated and a CQI indicator for requesting channel quality information is added to the allocation information to be transmitted to a subscriber station. The subscriber station having received the uplink radio resource allocation information generates channel quality information by measuring the radio channel quality for communication with the base station according to existence of the indicator and transmits desired uplink data having the generated channel quality information to the base station. As a result, the seamless and efficient channel quality report can be performed in the wireless communication system, and the optical modulation and the channel coding level can be adapted for the subscriber to transmit or receive the data corresponding to the channel quality. ing the channel quality information to the header of the uplink data.