Noise Power Estimation Using Unused Orthogonal Spreading Codes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional noise estimation techniques in digital receivers are complex, sensitive to unexpected user transmissions, and prone to significant estimation errors, especially in control channels with limited pilot symbols and active users.
Innovation Solution
The method estimates noise power by despreading unused orthogonal spreading codes, which are not assigned to any user, allowing for accurate noise observation without interference from active signals, thus reducing complexity and error.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional noise estimation techniques are used in digital receivers, then noise power can be estimated, but the complexity increases and estimation errors become significant
Solution Approach 1:
The patent extracts the noise estimation function from conventional complex techniques by utilizing unused orthogonal spreading codes. Instead of processing active user signals through complex algorithms, the system isolates noise by despreadsing received signals with non-assigned codes, thereby simplifying the receiver architecture while maintaining or improving estimation accuracy.
Solution Approach 2:
The unused orthogonal spreading codes serve as an intermediary medium for noise estimation. These non-assigned codes act as a bridge between the received signal and noise power measurement, allowing the receiver to observe noise without direct interference from active user transmissions, thus reducing complexity and improving accuracy.
2Reliability
If conventional noise estimation techniques are used, then noise power can be estimated, but the estimation becomes sensitive to unexpected user transmissions
Solution Approach 1:
The patent removes the harmful sensitivity to unexpected user transmissions by extracting noise estimation from active signal processing. By using unused orthogonal spreading codes that are not assigned to any user, the system isolates noise observations from the interference of unexpected transmissions, thereby improving reliability.
Solution Approach 2:
The patent converts the potential harm of unexpected user transmissions into a benefit by using unused codes. Instead of being disrupted by unexpected transmissions on assigned codes, the system benefits from having dedicated non-assigned codes that provide clean noise observation channels, transforming a potential problem into a solution.
3Measurement precision
If pilot symbols are used for noise estimation in control channels, then noise power can be estimated, but significant estimation errors occur due to limited pilot symbols and active users
Solution Approach 1:
The patent extracts noise estimation from the limited pilot symbol set by utilizing unused orthogonal spreading codes. Instead of relying on a small number of pilot symbols that are contaminated by active user signals, the system uses non-assigned codes to observe noise directly, thereby achieving accurate estimation without requiring large quantities of pilot symbols.
Solution Approach 2:
The unused orthogonal spreading codes serve multiple functions: they maintain orthogonality in the code division multiplexing system while simultaneously providing dedicated channels for noise estimation. This multi-functionality allows the same code structure to support both user communication and accurate noise measurement without requiring separate resources.
Data Source
AI summary
A receiving device in a communication system is provided. The communication system includes at least one processor configured to estimate noise power on a frequency channel by despreading a reception on the frequency channel using at least one non-assigned despreading code. The at least one non-assigned despreading code corresponds to at least one spreading code that is unused by transmitting devices in the communication system on the frequency channel.