PUCCH Cyclic Shift Scheme for Multi-Carrier UCI Transmission
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Solution Overview
Problem
In next-generation mobile communication systems, expanding the number of component carriers in user terminals beyond five poses challenges for transmitting uplink control signals effectively, as existing systems are insufficient to handle the increased capacity, particularly for 6 or more configured component carriers.
Innovation Solution
A new PUCCH format is introduced that applies cyclic shifts to first symbols for demodulation reference signals and uses orthogonal codes with shorter sequence lengths than existing formats for second symbols, enabling efficient transmission of uplink control signals by orthogonal-division-multiplexing with existing PUCCH or PUSCH formats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of component carriers is expanded to six or more, then the wireless communication capacity and flexibility are improved, but the existing PUCCH transmission methods become insufficient and require new transmission methods
Solution Approach 1:
The patent changes the parameters of the PUCCH format by applying cyclic shifts to the first symbol for demodulation reference signal and using orthogonal codes with shorter sequence lengths for the second symbol. This allows the system to accommodate six or more component carriers while maintaining efficient resource utilization and avoiding the need for completely new transmission methodologies.
2Ease of operation
If existing PUCCH format is used for six or more component carriers, then the transmission method remains simple and compatible, but the uplink control signals cannot be properly transmitted
Solution Approach 1:
The patent introduces dynamic parameters into the PUCCH format by applying cyclic shifts to the first symbol and using orthogonal codes for the second symbol. This dynamic approach allows the system to adapt to six or more component carriers, ensuring reliable uplink control signal transmission while maintaining a degree of operational simplicity through structured modifications rather than complete redesign.
3Adaptability or versatility
If orthogonal codes with longer sequence lengths are used, then the existing PUCCH format compatibility is maintained, but the resource overhead increases and efficiency decreases
Solution Approach 1:
The patent applies different orthogonal code characteristics to different symbols within the PUCCH structure. Specifically, the first symbol uses cyclic shifts for demodulation reference signal while the second symbol uses orthogonal codes with shorter sequence lengths. This localized differentiation optimizes resource utilization and reduces overhead while maintaining necessary compatibility.
Data Source
AI summary
A terminal is disclosed that includes a processor that determines a cyclic shift to be applied to a demodulation reference signal, based on a plurality of candidates configured by higher layer signaling and based on a field, for indicating a physical uplink control channel (PUCCH) resource for an uplink control information (UCI), included in a downlink control information. The terminal further includes a transmitter that transmits the UCI using a PUCCH format, in which the determined cyclic shift is applied to the demodulation reference signal and to which an orthogonal code having a sequence length less than 5 is applied, where the processor controls a frequency-domain orthogonal cover code (freq-domain OCC) to be applied for the PUCCH format, and where a number of bits of the UCI is more than 2. In other aspects, a base station and another terminal are also disclosed.