Uplink Control Signal Separation Using Distinct DFT Operations
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Solution Overview
Problem
Conventional multiple carrier communication systems, such as DFT-S-OFDM, do not efficiently distinguish between ACK/NACK and CQI signals when transmitting non-data-associated control information in the uplink, leading to inefficient utilization of frequency resources and difficulty in demodulating signals from multiple users sharing the same resource unit.
Innovation Solution
The method involves separately spreading ACK/NACK and CQI control information using different DFTs before mapping them to subcarriers, allowing the base station to distinguish between these signals and improve frequency resource allocation, thereby enhancing the bit error rate (BER) and peak-to-average power ratio (PAPR) performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ACK/NACK and CQI control information are transmitted together using the same DFT and subcarrier mapping, then frequency resource utilization is simplified, but the base station cannot distinguish between different control signals and demodulation becomes difficult
Solution Approach 1:
The patent segments the control information processing by applying different DFT operations to ACK/NACK and CQI signals. Specifically, ACK/NACK signals undergo a first DFT while CQI signals undergo a second DFT, creating distinct transformed domains that enable reliable distinction at the base station without increasing overall system complexity
2Productivity
If multiple users share the same resource unit for uplink transmission, then frequency resource allocation is efficient, but signals from different users cannot be distinguished and demodulated
Solution Approach 1:
The patent applies local quality differentiation by using distinct DFT parameters for different control signal types. Each control signal type (ACK/NACK and CQI) receives a specific DFT operation tailored to its characteristics, enabling the base station to identify and demodulate signals from multiple users sharing the same resource unit without interference
3Ease of manufacture
If control information is not separately processed, then transmission is simplified, but frequency resources are wasted and BER performance deteriorates
Solution Approach 1:
The patent performs preliminary action by applying different DFT operations to ACK/NACK and CQI signals before they are mapped to subcarriers. This preliminary differentiation ensures that even though the signals are transmitted together using the same resource units, the base station can reliably distinguish and demodulate each signal type, improving BER performance without complicating the overall transmission process
Data Source
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Figure 2A~2B
Figure 2C
AI summary
A portable device, such as a mobile terminal or user equipment, for encoding uplink acknowledgments to downlink transmissions. The portable device includes a receiver configured to receive a plurality of data blocks, such that each of the data blocks include an associated cyclic redundancy check (CRC), and a processor configured to determine received status for each of the data blocks by checking the CRC of each of the data blocks. The portable device further includes a transmitter for transmitting a response sequence which indicates the received status of all of the data blocks.