USF Coding via Constellation Encoding
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Solution Overview
Problem
Current cellular network protocols face challenges in reliably transmitting uplink state flag (USF) information due to limited physical communication resources, where multiple mobile stations share the same frequency channel, leading to potential errors in scheduling uplink traffic.
Innovation Solution
The implementation of a constellation-corner-based encoding scheme by the base station to encode USF bits into a plurality of symbols, which are then interleaved and modulated using QAM, allowing for more resilient transmission and accurate interpretation by mobile stations, even in noisy conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple mobile stations share the same frequency channel, then channel utilization is improved, but transmission reliability of USF information deteriorates
Solution Approach 1:
The USF information is segmented into multiple separate transmissions embedded within different downlink data packets. Instead of transmitting USF once, it is distributed across multiple packets, so that even if some packets are lost or corrupted due to channel sharing conflicts, the USF information can still be recovered from other packets.
Solution Approach 2:
The system prepares for potential transmission errors by embedding USF information in advance within multiple downlink packets before any error occurs. This proactive approach ensures that redundant copies of the scheduling information are already in place to cushion against future transmission failures in the shared channel environment.
2Reliability
If USF is strongly encoded with Hamming distance, then transmission reliability is improved, but data rate deteriorates
Solution Approach 1:
The downlink data packets serve multiple functions simultaneously: they carry both the actual data payload and the USF scheduling information. By embedding USF within the data packets rather than transmitting it separately, the system achieves reliable USF transmission without dedicating additional channel resources, thus maintaining high data rates while ensuring reliability.
Solution Approach 2:
The USF information is merged with the downlink data transmission. Instead of separate encoding and transmission of USF, the scheduling information is combined with the data packets, allowing the same channel resources to serve dual purposes and avoiding the data rate penalty of separate strong encoding.
3Reliability
If USF bits are encoded into more symbols, then error resilience is improved, but processing complexity increases
Solution Approach 1:
The system uses the existing downlink packet structure and modulation schemes already in place for data transmission to carry the USF information. Rather than introducing new complex encoding and modulation specifically for USF, the system leverages the existing communication infrastructure to self-serve the dual purpose of data and scheduling information transmission.
Data Source
AI summary
Systems and methods are provided for transmitting and receiving an uplink state flag (USF) in a cellular network. A base station may transmit the USF to plurality of mobile stations that share the same frequency channel, and each mobile station can use the USF to determine whether that mobile station can transmit data in an upcoming uplink time period. The base station can encode the USF bits into a plurality of encoded USF symbols, where the encoded USF symbols may be selected from corner signal points in a QAM signal constellation set or from signal points adjacent to the corners of a QAM signal constellation set. The base station can interleave the encoded USF symbols and modulate the encoded USF symbols for transmission using the signal constellation set. A mobile station that can communication with the base station can include a corresponding receiver, de-interleaver, and decoder.