Abstract: In certain embodiments, a method for managing operational parameters of a cognitive radio device to minimize non-compliance with a regulatory policy involves sensing a change in an operational condition that will affect compliance with a current operational policy; estimating a time at which the current operational policy will become invalid; selecting a method for determining how to update the current operational policy; and updating the current operational policy of the cognitive radio device. Other embodiments may incorporate more, fewer or other elements.

Abstract: Performance of a radio device is optimized by estimating if the device is inside a building. One or more sensors on the radio device are used to measure an environmental quantities relating to the environment of the radio device. The likelihood of the radio device being inside a building is inferred from these measurements. The operation of the radio device then is controlled accordingly. For example, if the radio device is determined to be inside a building, a low operating frequency may be selected for the radio device if a wide area network connection is required, while a high operating frequency may be selected if a local connection is required. An environmental quantity may be, for example, a satellite signal, ambient light, temperature, RF energy, or the response to a test signal emitted by the radio device.

Abstract: In certain embodiments of a cognitive radio, a method of establishing operational policies, involves determining that a new policy decision should be made; requesting a policy decision from an authority having more computing power than the cognitive radio; receiving the policy decision from the authority; and implementing the policy decision in the cognitive radio. Other embodiments may incorporate more, fewer or other elements.

Abstract: A phase demodulator (101) is used for sensing the phase.sub.-- angle of a phasor represented by the I and Q signals by first producing the analog I and Q signals in a direct conversion receiver (104). A phase generator (106) is used to approximate the angle of the phasor as represented by the I and Q signals by scaling and comparing the magnitudes of the I and Q signals and making decisions based on their relative magnitudes. The scaling includes successive alteration of the magnitude of the I and Q signals.sub.-- depending on their relative magnitudes. A DSP (108) is used to receive this bit stream representation (302) of the phasor and recover the information signal.

Abstract: A method and means for quadrature amplitude modulation is described. The improved QAM modulator circuit utilizes a small read only memory to hold multiple versions of a signal constellation resulting in the elimination of hardware modulator circuits. In addition, the described device can be potentially any modulation scheme on an input signal which is sampled in time by modifying the contents of said ROM.

Abstract: Voice signals subjected to differential modulation such as CVSD modulation are made more intelligible by differentiating an electrical analog of the voice signal, clipping peaks of the differentiated signal, integrating the clipped differentiated signal, and applying the integrated signal to a differential modulator such as a CVSD modulator.

Abstract: A plurality of up/down counters are controlled by a programmed digital reference signal. The combination of a high select signal and a high input signal causes any one of the counters to increment (up) by one count while a combination of a high select signal and a low input signal causes any one of the counters to decrement (down) one count. A threshold detector signals on output when a specific combination of the counters reaches a predetermined combination count signifying correlation of the programmed reference with the input tone over a predetermined number of cycles. The phase of the input may be determined by noting which of the counters reaches the predetermined threshold.

Abstract: A digital signal detector is disclosed that detects a serial bit stream transmitted at a predetermined bit frequency. Bit transitions are totallized in a counter over a predetermined time interval. Bit transitions occurring during a good window interval increment the totallized count by one. Bit transitions occurring during a bad window interval decrement the totallized count by one. Bit transitions occurring during a marginal window interval, situated between the good and bad window intervals, do not affect the totallized count. If the counter reaches a predetermined count during the time interval, a detect signal is provided indicating that the digital signal has been detected. The counter can be further loaded with a threshold count for tailoring the digital signal detector for operation at a particular signal-to-noise ratio. Periodic signals that have frequencies that are submultiples of the bit frequency are detected by correlating the digital signal between two predetermined stages of a shift register.

Abstract: A detector for delta modulated digital signals is disclosed that provides a signal quality voltage having a magnitude that is indicative of the degree of quality of the detected delta modulated digital signal. The detector totalizes the number of bit transitions occurring in successive N bit intervals. If successive totalized numbers of bit transitions are outside of a predetermined range centered about one-half of N, the detector provides a detect indication signal indicating that the delta modulated digital signal is present. Otherwise, a random or pseudorandom signal such as noise or error bursts may be present. Digital circuitry provides the detect indication signal with a logical high state when successive totalized numbers of bit transitions are outside of the predetermined range, and a logical low state when succesive totalized numbers of bit transitions are within the predetermined range.