Abstract: An information handling system includes a power supply coupled to a processor that includes a plurality of cores. A power system controller is coupled to the power supply and the processor. The power system controller may set each of the plurality of cores to a performance state that is below a highest performance state. The power system controller may then determine whether the power supplied from the power supply to the processor during operation is sufficient to operate each of the plurality of cores at the highest performance state. In response to the power being insufficient to operate each of the plurality of cores at the highest performance state, the power system controller may control the plurality of cores such that a subset operate at the highest performance state and the remainder operate at a performance state that is lower than the highest performance state.

Abstract: An information handling system includes a power supply coupled to a processor that includes a plurality of cores. A power system controller is coupled to the power supply and the processor. The power system controller may set each of the plurality of cores to a performance state that is below a highest performance state. The power system controller may then determine whether the power supplied from the power supply to the processor during operation is sufficient to operate each of the plurality of cores at the highest performance state. In response to the power being insufficient to operate each of the plurality of cores at the highest performance state, the power system controller may control the plurality of cores such that a subset operate at the highest performance state and the remainder operate at a performance state that is lower than the highest performance state.

Abstract: An information handling system includes a power supply coupled to a processor that includes a plurality of cores. A power system controller is coupled to the power supply and the processor. The power system controller may set each of the plurality of cores to a performance state that is below a highest performance state. The power system controller may then determine whether the power supplied from the power supply to the processor during operation is sufficient to operate each of the plurality of cores at the highest performance state. In response to the power being insufficient to operate each of the plurality of cores at the highest performance state, the power system controller may control the plurality of cores such that a subset operate at the highest performance state and the remainder operate at a performance state that is lower than the highest performance state.

Abstract: A spectrum sensing method for cognitive radio wherein spectrum holes are detected in a wireless environment having spectrum scarcity. First, a cognitive radio user (CR) determines the power spectral density (PSD) of a wideband signal and detects subbands within the wideband using wavelet transforms (WT). WT coefficients are calculated by convolving the PSD with first derivatives of wavelet smoothing functions. The extrema of the WT coefficients demark frequency subband edges. Detecting subband edges becomes more robust against noise by median filtering the PSD before calculating WT coefficients, summing over WT coefficients with different scale factors, and suppressing WT coefficients below a noise threshold. After identifying subbands, the CR determines subband availability by measuring the subband power and signaling the power to a fusion center receiving power measurements from multiple cooperating CRs, and final decisions are based on data and decision fusion.

Abstract: A spectrum sensing method for cognitive radio to detect spectrum holes in an environment of bandwidth scarcity. The method comprises first receiving a wireless signal at a cognitive radio user, and then discovering the frequency edges of allocated frequency bands by using wavelet transform coefficients to detect discontinuities in the power spectral density of the received signal. After determining the allocated frequency bands, the method determines frequency band availability by detecting the in band energy using a bi-threshold energy detector, where the energy detector makes hard decisions and soft decisions. Finally, a fusion center combines hard and soft decisions collected from a cooperative spectrum sensing network of cognitive radio users and makes a final decision using a hybrid of data fusion and decision fusion to determine the final decision regarding spectrum availability.

Abstract: A spectrum sensing method for cognitive radio wherein spectrum holes are detected in a wireless environment having spectrum scarcity. First, a cognitive radio user (CR) determines the power spectral density (PSD) of a wideband signal and detects subbands within the wideband using wavelet transforms (WT). WT coefficients are calculated by convolving the PSD with first derivatives of wavelet smoothing functions. The extrema of the WT coefficients demark frequency subband edges. Detecting subband edges becomes more robust against noise by median filtering the PSD before calculating WT coefficients, summing over WT coefficients with different scale factors, and suppressing WT coefficients below a noise threshold. After identifying subbands, the CR determines subband availability by measuring the subband power and signaling the power to a fusion center receiving power measurements from multiple cooperating CRs, and final decisions are based on data and decision fusion.

Abstract: A spectrum sensing method for cognitive radio to detect spectrum holes in an environment of bandwidth scarcity. The method comprises first receiving a wireless signal at a cognitive radio user, and then discovering the frequency edges of allocated frequency bands by using wavelet transform coefficients to detect discontinuities in the power spectral density of the received signal. After determining the allocated frequency bands, the method determines frequency band availability by detecting the in band energy using a bi-threshold energy detector, where the energy detector makes hard decisions and soft decisions. Finally, a fusion center combines hard and soft decisions collected from a cooperative spectrum sensing network of cognitive radio users and makes a final decision using a hybrid of data fusion and decision fusion to determine the final decision regarding spectrum availability.

Abstract: An information handling system includes a power supply coupled to a processor that includes a plurality of cores. A power system controller is coupled to the power supply and the processor. The power system controller may set each of the plurality of cores to a performance state that is below a highest performance state. The power system controller may then determine whether the power supplied from the power supply to the processor during operation is sufficient to operate each of the plurality of cores at the highest performance state. In response to the power being insufficient to operate each of the plurality of cores at the highest performance state, the power system controller may control the plurality of cores such that a subset operate at the highest performance state and the remainder operate at a performance state that is lower than the highest performance state.

Abstract: Systems and methods are disclosed for power management in information handling systems using processor performance data to validate changes to processor performance states. Processor utilization data and processor performance data is obtained during system operation. The processor utilization data is analyzed to determine a desired performance state for the processor. Before setting the actual performance state of the processor to this desired performance state, however, processor performance data is analyzed to determine if prior changes to the performance state have been effective. The performance state of the processor is then changed are maintained based upon this additional performance verification analysis.

Abstract: Systems and methods are disclosed for power management in information handling systems using processor performance data to validate changes to processor performance states. Processor utilization data and processor performance data is obtained during system operation. The processor utilization data is analyzed to determine a desired performance state for the processor. Before setting the actual performance state of the processor to this desired performance state, however, processor performance data is analyzed to determine if prior changes to the performance state have been effective. The performance state of the processor is then changed are maintained based upon this additional performance verification analysis.