Noise Interference Power Estimation Using Correlation Values
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Solution Overview
Problem
Estimating Noise and Interference (NI) power in IEEE 802.16 communication systems using periodic ranging operations is prone to increased error probability due to the absence of reference signals and code collisions, which affects power control and system performance.
Innovation Solution
An apparatus and method that utilize correlation values between ranging subcarriers and codes to detect desired and remaining ranging codes, estimate NI power, and combine values from multiple antennas to accurately calculate NI power, reducing error probability through correlation-based estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If periodic ranging operation is performed without reference signal, then power control can be implemented, but error probability in NI power estimation increases
Solution Approach 1:
The patent uses correlation values as an intermediary to estimate NI power. Instead of directly measuring NI power without reference signals, the system calculates correlation values between received ranging subcarriers and local ranging codes, then uses these correlation values to derive NI power estimates. This intermediary approach enables power control while reducing estimation errors.
Solution Approach 2:
The patent replaces traditional reference signal-based NI power estimation with a correlation-based computational approach. By substituting the mechanical/reference signal dependency with signal processing operations (correlation calculation and processing), the system achieves reliable NI power estimation without requiring separate reference signals.
2Adaptability or versatility
If contention-based periodic ranging operation is used, then system flexibility is improved, but code collision increases leading to higher error probability
Solution Approach 1:
The patent extracts and removes the effects of desired ranging codes from the correlation values before estimating NI power. By separating the signal component (desired code correlation) from the noise and interference components, the system can maintain contention-based operation flexibility while achieving accurate NI power estimation by focusing only on the remaining noise and interference portions.
3Reliability
If NI power estimation error occurs, then power control error increases, but system performance reduction is avoided through improved estimation methods
Solution Approach 1:
The patent implements a feedback mechanism where correlation values from multiple ranging codes are processed to provide more reliable NI power estimates. By utilizing information from multiple codes and iteratively processing correlation values, the system reduces estimation errors and provides more accurate feedback for power control decisions, thereby preventing system performance degradation.
Data Source
AI summary
A method is provided for estimating a Noise and Interference (NI) power in a ranging code reception apparatus in a communication system. The method includes generating S correlation values by calculating correlations between L ranging subcarriers received at a ranging code reception apparatus and L elements included in each of S ranging codes available in the ranging code reception apparatus, detecting N reception-desired ranging codes that the ranging code reception apparatus desires to receive, among the S ranging codes, using the S correlation values, and selecting M remaining ranging codes among (S-N) ranging codes obtained by removing the N reception-desired ranging codes from the S ranging codes, and estimating a first NI power using correlation values for the M remaining ranging codes.