Cell-Specific Wake-Up Signal Design for Wireless Node Power Optimization
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Solution Overview
Problem
Existing wake-up signals in wireless communication networks are not effectively cell-specific, leading to unnecessary power consumption and interference, as they are not easily receivable by wake-up receivers without being scrambled with cell identity, making it challenging to awaken only targeted communication nodes while conserving battery life.
Innovation Solution
A cell-specific wake-up signal is generated and transmitted using binary sequences based on Zadoff-Chu sequences or error correcting codes, allowing for cell-specific reception with a wake-up receiver, enabling targeted awakening of communication nodes and reducing power consumption by using a lower power receiver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a wake-up signal is scrambled with cell identity to be cell-specific, then interference between cells is reduced and targeted awakening is achieved, but the complexity of the wake-up receiver increases and power efficiency deteriorates
Solution Approach 1:
The wake-up signal structure is segmented into two parts: a cell-specific sequence (such as PSS/SSS or Zadoff-Chu sequence with specific root index) that identifies the cell, and a wake-up indication part that triggers the device. This segmentation allows the wake-up receiver to detect cell identity without needing to decode the full PDCCH, reducing receiver complexity while maintaining cell-specificity.
Solution Approach 2:
The cell identity information is extracted from the wake-up signal structure as a separate detectable element (through sequence selection or specific resource element mapping) rather than being embedded within the full PDCCH message. This extraction enables the low-power wake-up receiver to identify the cell without processing the entire control channel, thus reducing complexity while preventing inter-cell interference.
2Reliability
If the main receiver monitors and decodes the downlink control channel to detect paging messages, then reliable communication is achieved, but device power consumption increases and battery life deteriorates
Solution Approach 1:
A simplified wake-up receiver performs preliminary detection of the wake-up signal before the main receiver is activated. This preliminary action filters out unnecessary PDCCH monitoring by detecting whether a wake-up indication is present, allowing the device to skip power-consuming full decoding operations when no paging message is intended, thus reducing power consumption while maintaining reliability through conditional main receiver activation.
Solution Approach 2:
The system dynamically switches between two receiver modes: a low-power wake-up receiver for initial signal detection and a high-performance main receiver for full message decoding. This dynamic adaptation allows the device to optimize power consumption by activating the main receiver only when necessary, based on the wake-up signal detection result, thereby balancing reliability and energy efficiency.
3Use of energy by moving object
If a wake-up receiver is used to monitor for wake-up signals, then power consumption is reduced, but the ability to receive other signals and channels deteriorates
Solution Approach 1:
The wake-up signal is designed to be receivable by both the simplified wake-up receiver and the full-capability main receiver. The signal structure (using standard synchronization sequences or control channel elements) ensures compatibility across different receiver types, allowing the wake-up receiver to perform its power-efficient monitoring function while the main receiver can handle additional signals and channels when activated, thus achieving both power savings and maintained versatility.
Data Source
AI summary
A first communication node (12) in a wireless communication network (10) monitors for a cell-specific wake-up signal (20). The first communication node (12) may monitor for the cell-specific wake-up signal (20) with a wake-up receiver (12W). The first communication node (12) in particular may monitor for a cell-specific wake-up signal (20) that is any of multiple cell-specific wake-up signals (20) in a set. In some embodiments, the set is re-used for different sets of cells. Alternatively or additionally, the set may include cell-specific wake-up signals (20) that are based on multiple respective binary sequences, based on different codewords of a binary error correcting code, based on different orthogonal sequences in a set, composed of different sets of Zadoff-Chu sequences with different roots, composed of the same set of Zadoff-Chu sequences with different cyclic shifts, or a function of different cyclic shifts of a root wake-up signal formed by multiple Zadoff-Chu sequences with different roots.