CAZAC Uplink Control Signaling for Higher User Multiplexing
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Solution Overview
Problem
In wireless telecommunications, the number of mobile devices that can be supported is limited by the number of reference signal sequences that can be generated, which restricts the capacity of cellular communications systems, especially in reverse link communications.
Innovation Solution
A method using constant amplitude zero-autocorrelation (CAZAC) sequences is employed for transmitting control information, where the CAZAC sequence is truncated and transmitted within a predetermined window of time, eliminating the need for reference signal demodulation and allowing for a larger number of sequences, thereby supporting more users with superior detection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If reference signal sequences are used for each mobile device, then detection performance is improved, but the number of supported mobile devices is limited by the number of available reference signal sequences
Solution Approach 1:
The patent divides a long CAZAC sequence into multiple shorter segments and transmits them in different time slots or frequency resources. This segmentation allows multiple mobile devices to share the same base CAZAC sequence through different segment assignments, thereby supporting more devices than the number of available full-length reference signal sequences while maintaining detection performance through the segmented structure
Solution Approach 2:
The patent changes the parameter of sequence length by using truncated or segmented versions of CAZAC sequences instead of full-length reference signal sequences. By adjusting the segment length and transmission timing, the system can support a larger number of mobile devices while preserving the essential correlation properties needed for detection
2Productivity
If a large number of reference signal sequences are generated to support more mobile devices, then system capacity is improved, but sequence generation complexity and overhead increase
Solution Approach 1:
The patent makes a single CAZAC sequence serve multiple functions by using it to generate segments for multiple different mobile devices. Instead of requiring unique reference signal sequences for each device, the same base CAZAC sequence is segmented and assigned to multiple users, reducing sequence generation complexity while maintaining system capacity
Solution Approach 2:
The patent creates multiple usable signal sequences by copying and segmenting a single base CAZAC sequence. The segmented copies are assigned to different mobile devices with appropriate time-frequency assignments, allowing the system to support more devices without generating entirely new sequences for each one
Data Source
AI summary
In one embodiment of the instant invention, a non-coherent transmission method for uplink control signals is provided. The transmission methodology uses a constant amplitude zero-autocorrelation (CAZAC) sequence for relatively short control signal lengths. The methodology includes creating a CAZAC sequence, truncating the CAZAC sequence into a plurality of segments; and transmitting each of the segments within a predetermined window of time.