Nokia Solutions and Networks Oy

Nokia Technologies Oy

Ramasamy Gopalan

Shavantha Kularatna

Darrell W Barabash

Linjie Leng

Sylwester Kominek

Yared Melese

Arnaud Pierrard

Artur Drozdz

Arthur Drozdz

A method, apparatus and computer program product is disclosed. The apparatus may comprise means for providing a model for a system for mitigating unwanted effects in a received signal and a means for determining a first curve, a, by performing autocorrelation of the model. The apparatus may also comprise means for determining a second curve, Xcorr, by performing cross-correlation of the model and a received signal comprising unwanted components due to first and second sources and means for estimating first and second delays associated with respective first and second sources based on the first and second curves, a, Xcorr. The unwanted effects in the received signal may be PIM products/components, but the disclosure is not limited to PIM alone, and embodiments may be used to mitigate or compute peaks in any interfering scenario where peaks may be hidden.

Estimating delays

An apparatus is disclosed, comprising means for determining a noise floor for a radio frequency (RF) system. The apparatus may also comprise means for determining a Passive InterModulation (PIM) value of a component of the RF system contributing as a source of PIM; determining that a passive intermodulation (PIM) cancellation system should be enabled if the PIM value is above a predetermined threshold from the noise floor. The apparatus may also comprise means for determining that the PIM cancellation system should be disabled if the PIM value is at or below the predetermined threshold.

PIM cancellation

An apparatus, method and work product is disclosed. The method comprises measuring plural transmit signals and corresponding receive signals and determining, using a model describing a relation between each of the plural transmit signals and a respective passive intermodulation signal, a standardized passive intermodulation signal as one or more nth order intermodulation products for a standardized transmit signal consisting of two tones each of a power of substantially 20 Watts. The method may also comprise identifying in the model one or more norder cross-intermodulation products resulting from three or more transmit signals having different respective carrier frequencies. Responsive to the identification, the method may comprise adapting the standardized two-tone passive intermodulation signal by determining an offset for producing an adapted two-tone standardized passive intermodulation signal, n is an odd integer greater than two.

Generalized virtual PIM measurement for enhanced accuracy

Methods, apparatus, and computer program products using spectrum analysis or cross correlation techniques to discriminate against interference. These approaches are straight forward if both the forward and reflected signals contain complex or quadrature (I and Q) samples. But, if only single axis samples are available as is often the case to reduce the sampling rate, the resulting samples could represent the I component, the Q component or, more likely, some combination of the two. This generally requires some type of time alignment procedure to ensure proper phase. Assuming that the transmitted signal exists in complex form, this signal can be mathematically rotated in phase and then single axis sampled for comparison against the single axis reflected signal. If the rotation is done over equally spaced intervals that spans one complete cycle, the average of the absolute value all such return loss ratios will approach the actual return loss ratio and the interference will be suppressed. The resultant can be compared to a threshold value and trigger an alarm.

Growing community of inventors

Irving, TX, United States of America

Ramasamy Gopalan