Control Channel Signal Generation Using Frequency Division Multiplexing
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Solution Overview
Problem
Current New Radio (NR) short physical uplink control channel (PUCCH) designs face challenges in providing coherent demodulation while maintaining low peak-to-average power ratio (PAPR) and low cubic metric (CM), especially on highly dispersive channels, with existing sequence modulation lacking desirable properties and sequence selection suffering from performance loss.
Innovation Solution
The solution involves generating a control channel with two multiplexed sequences based on a base sequence, where even samples are modulated for one sequence and odd samples for another, using frequency division multiplexing, and restricting modulation to BPSK, allowing for coherent demodulation and low PAPR/CM, while enabling multiple users to share the same time-frequency resource by allocating additional cyclic shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sequence modulation is used for coherent demodulation, then demodulation performance is improved, but peak-to-average power ratio (PAPR) increases
Solution Approach 1:
The patent divides the control channel transmission into two separate sequences: a first sequence for uplink control information (UCI) and a second sequence for demodulation reference signals (DM-RS). This segmentation allows the DM-RS sequence to be designed with low PAPR properties while the UCI sequence carries the control data, resolving the contradiction between coherent demodulation requirements and low PAPR constraints.
Solution Approach 2:
The patent introduces a separate DM-RS sequence as an intermediary element that enables coherent demodulation without requiring the UCI sequence itself to have high power characteristics. The DM-RS acts as a mediator that provides the reference signals needed for coherent demodulation while maintaining low PAPR, allowing the UCI to be transmitted with appropriate power levels.
2Use of energy by moving object
If sequence selection is used to maintain low PAPR, then peak-to-average power ratio is reduced, but coherent demodulation capability is lost
Solution Approach 1:
The patent segments the transmission into distinct UCI and DM-RS sequences, allowing the DM-RS sequence to be specifically optimized for low PAPR while providing the necessary reference signals for coherent demodulation. This segmentation enables the system to achieve both low PAPR and coherent demodulation capability simultaneously.
Solution Approach 2:
The DM-RS sequence serves multiple functions: it provides reference signals for coherent demodulation, maintains low PAPR characteristics, and enables reliable UCI transmission. This multi-functionality allows the system to achieve coherent demodulation without sacrificing PAPR performance.
3Productivity
If multiple users are multiplexed on the same PRB with sequence modulation, then multiplexing capacity is increased, but PAPR remains high
Solution Approach 1:
The patent segments the multiplexed transmission into separate UCI and DM-RS sequences for each user, allowing independent optimization of each sequence's PAPR characteristics while maintaining the ability to multiplex multiple users on the same physical resource block. This segmentation enables scalable multiplexing capacity without proportionally increasing PAPR.
Solution Approach 2:
The patent changes the structural parameters of the control channel by separating UCI and DM-RS into distinct sequences with different modulation and coding schemes. This parameter change allows each sequence to be optimized for its specific function, enabling multiple users to be multiplexed with controlled PAPR through appropriate sequence design and resource allocation.
Data Source
AI summary
A method, wireless device and network node are configured to generate or process a control channel, having two multiplexed sequences based on a base sequence. In some embodiments, a method includes sampling even samples of the base sequence and modulating the sampled even samples to create a first control channel sequence. The method includes performing a second sampling of odd samples of the base sequence to create a second control channel sequence. The method also includes frequency division multiplexing the first and second control channel sequences to produce the control channel.