Spatially Coded OFDM Clipping for CF-mMIMO PAPR Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CF-mMIMO systems based on OFDM signal transmission have high peak-to-average power ratios (PAPR), which are not effectively reduced by traditional methods, limiting their scalability and energy efficiency, especially in scenarios where the number of receivers exceeds the number of transmit antennas.
Innovation Solution
A method involving spatial coding of distortion signals from clipping, transmitting these signals towards receivers with higher propagation loss, thus avoiding strong receivers and optimizing PAPR reduction in scalable CF-mMIMO systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional PAPR reduction methods are applied to CF-mMIMO systems, then some PAPR reduction is achieved, but the methods are not effective enough and increase computational complexity
Solution Approach 1:
The invention segments the distortion signal into multiple components corresponding to different spatial directions. By dividing the distortion signal processing into directional segments, the system can apply targeted spatial coding to each segment, reducing overall PAPR while maintaining manageable computational complexity through structured processing.
Solution Approach 2:
The invention transitions from traditional single-dimensional PAPR reduction methods to multi-dimensional spatial coding in the angular domain. By exploiting the spatial dimension and directing distortion signals to specific angular regions, the system achieves effective PAPR reduction without proportionally increasing computational burden.
2Adaptability or versatility
If the number of receivers exceeds the number of transmit antennas, then system coverage is improved, but PAPR reduction becomes more difficult and traditional methods fail
Solution Approach 1:
The invention applies local quality by directing distortion signals to specific spatial regions corresponding to weak receivers rather than uniformly processing all receivers. This localized approach allows the system to maintain scalability with more receivers than antennas, as the spatial coding targets specific directional regions rather than requiring proportional increases in transmit antenna resources.
3Reliability
If distortion signals are transmitted towards strong receivers, then signal quality is maintained, but PAPR reduction effectiveness is reduced
Solution Approach 1:
The invention converts the harmful distortion signals into a beneficial tool for PAPR reduction by spatially directing them towards weak receivers where they cause minimal interference. Instead of treating distortion signals as purely harmful elements to be eliminated, the system exploits them to achieve the dual benefit of PAPR reduction and acceptable signal quality at weak receiver locations.
Data Source
AI summary
The invention relates to a method for reducing the peak-to-average power ratio of an OFDM-type signal comprising N subcarriers. The signal results from stacking M spatial components that are each transmitted by a respective antenna of a radiofrequency transmitter to a plurality of receivers. Such a method uses spatial coding of the distortion signal associated with clipping the OFDM signal transmitted by the transmitter so that the distortion signal in question is transmitted in the direction of a receiver for which the estimated propagation channel, between the receiver in question and the transmitter, corresponds to a path loss greater than a predetermined threshold.