Koninklijke Philips Corporation N.v.

Gennady Turkenich

Dagnachew Birru

Viktor L Gornstein

David Koo

Patrick D Kelliher

A method () and system () for detecting temporarily available bandwidth in a frequency band: select () a channel in the frequency band; measure () an energy received in the selected channel; compare () the measured energy to a first threshold; when the measured energy exceeds the first threshold, determine that the channel is unavailable () for transmission, otherwise determine () that the channel is available for transmission; correlate () a signal received in the channel with a known feature of a signal conforming to a particular transmission format; compare () the correlation result to a second threshold; when the correlation result in the channel exceeds the second threshold, determine () that a signal conforming to the particular transmission format is present in the channel, otherwise determine () that the signal conforming to the particular transmission format is not present in the channel.

System and method for detecting temporarily unused bandwidth in the RF spectrum

An input signal is filtered for creating an output signal using an adaptive filter. An error signal is derived from the output signal. The adaptive filter has coefficient whose value can be modified. A value of a coefficient is modified using a derived updating amount. The updating amount is obtained from the product of a value of the input signal, a value of the polarity of the error signal, and a step gain. The step gain has the form 2with K being an integer and being dependent on a magnitude of the value of the error signal and on a step gain parameter. The updating amount is dependent on both the magnitude and the polarity of the error signal, therefore allowing a precise update of the coefficient. The specific form of the step gain allows a fast derivation of the product.

Adaptive filtering method and related device

A round off mechanism maintains a mean value of the operand while rounding twos complement binary data. Positive data values are incremented at the first discard bit prior to truncation of the discard bits, as are negative data values having a one within the most significant discard bit and at least one other discard bit. The discard bits are simply truncated for all other negative data values.

Round-off algorithm without bias for 2's complement data

There is disclosed a digital filter cell capable of processing in a first mode a first signal having real data components only and processing in a second mode a second signal having real data components and imaginary data components. The digital filter cell comprises: 1) a plurality of serially coupled coefficient registers for receiving a sequence of coefficients; 2) a plurality of serially coupled data registers for receiving a sequence of digital data samples, each register having a tap output; 3) a data multiplexer having a plurality of input channels for receiving the tap outputs from the plurality of serially coupled data registers; and 4) a product summation circuit having a first input coupled to an output of the data multiplexer and a second input coupled to an output of a selected one of the plurality of serially coupled coefficient registers. The product summation circuit generates a summation of a plurality of products formed by sequentially multiplying each coefficient received from the selected coefficient register by a corresponding digital data sample received from a selected one of the plurality of serially coupled data registers. The product summation circuit adds each of the plurality of products to the summation when the digital filter cell is operating in the first mode. In the second mode, the product summation circuit selectively adds ones of the plurality of products to the summation or selectively subtracts ones of the plurality of products from the summation.

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Hillsdale, NJ, United States of America

Gennady Turkenich