Abstract: A method and apparatus for compensation of noise in a Radio Frequency Identification (RFID) device through modulation of a received signal is described. The method includes determining an amplitude signal proportional to an amplitude of a transmitter signal and associated noise; processing the amplitude signal to derive a correction signal; and modulating a received signal during a receive period with the correction signal to substantially remove the associated noise from the received signal. An RFID device and an RFID transceiver integrated circuit (IC) are also described.

Abstract: A method and apparatus for compensation of noise in a Radio Frequency Identification (RFID) device through modulation of a received signal is described. The method includes determining an amplitude signal proportional to an amplitude of a transmitter signal and associated noise; processing the amplitude signal to derive a correction signal; and modulating a received signal during a receive period with the correction signal to substantially remove the associated noise from the received signal. An RFID device and an RFID transceiver integrated circuit (IC) are also described.

Abstract: A mixer, a receiver, and a method provide dynamic sub-sampling mixer which adjust a sub-sampling rate based on power drain and performance. A mixer includes mixer circuitry receiving an input of a Radio Frequency (RF) input signal and providing an output of a baseband signal of the RF input sampled at a sub-sampling rate, baseband parametric control circuitry receiving the baseband signal and measuring at least one parametric value of the baseband signal, and sampling period control circuitry receiving the at least one parametric value and adjusting the sub-sampling rate based thereon, the sub-sampling rate or ratio is adjusted minimize power drain while ensuring performance of the at least one parametric value is satisfying a predetermined level.

Abstract: A mixer, a receiver, and a method provide dynamic sub-sampling mixer which adjust a sub-sampling rate based on power drain and performance. A mixer includes mixer circuitry receiving an input of a Radio Frequency (RF) input signal and providing an output of a baseband signal of the RF input sampled at a sub-sampling rate, baseband parametric control circuitry receiving the baseband signal and measuring at least one parametric value of the baseband signal, and sampling period control circuitry receiving the at least one parametric value and adjusting the sub-sampling rate based thereon, the sub-sampling rate or ratio is adjusted minimize power drain while ensuring performance of the at least one parametric value is satisfying a predetermined level.

Abstract: A communications system and method for exchanging spectrum usage information through a drop box (100) includes one or more central stations (101) that defines a region of operation. A central drop box (102) is associated with the central station (101) for providing a database of spectrum usage information. Stations (103, 105, 107) using the communications system may submit information regarding spectrum usage to the central drop box (102) that affects the region of operation (109, 115) for providing the most efficient and non-interfering uses of the frequency spectrum.

Abstract: Communication devices and methods for transmitting and receiving a wideband signal using aggregated discontiguous narrowband channels in a band are presented. During transmission, a fold point is determined in which symmetric free channels are sufficient to transmit the signal. The signal is then synthesized by aggregating the data in the channels and transmitted using the fold point as the up-conversion modulation frequency. During reception, information regarding which channels are being used to provide data signals and which channels are occupied by interferers is received. This information is used to determine one or more fold points as the down-conversion modulation frequencies. The fold points are selected such that an image of each interferer falls on an unoccupied channel or a narrowband channel occupied by another interferer.

Abstract: A frequency generation unit is provided that permits a receiver to tune from channel to channel without cycle skipping and in which compensation for phase offset introduced during tuning is provided. The frequency generation unit includes a fractional-N synthesizer, a voltage controlled oscillator (VCO), and a direct digital synthesizer (DDS). The fractional-N synthesizer generates frequencies from the VCO as well as a temperature controlled crystal oscillator. Outputs from the fractional-N synthesizer are supplied both the VCO and the DDS to control the VCO and DDS. The combination of the voltage controlled oscillator and fractional-N synthesizer is perpetually locked. The fractional-N synthesizer is maintained in a locked condition. The VCO output is provided to the DDS. An output from the DDS or from the fractional-N synthesizer forms the output signal of the frequency generation unit.

Abstract: A cognitive radio (CR) device (208 and/or 218) avoids interference with an incumbent (207) receiver by determining maximum allowed transmit power levels of the CR device based on estimates of the incumbent signal level and transmit splatter levels of the CR device. The CR device (208 and/or 218) avoids interference with the incumbent receiver while transmitting with maximum transmit power levels.

Abstract: A frequency generation unit is provided that permits a receiver to tune from channel to channel without cycle skipping and in which compensation for phase offset introduced during tuning is provided. The frequency generation unit includes a fractional-N synthesizer, a voltage controlled oscillator (VCO), and a direct digital synthesizer (DDS). The fractional-N synthesizer generates frequencies from the VCO as well as a temperature controlled crystal oscillator. Outputs from the fractional-N synthesizer are supplied both the VCO and the DDS to control the VCO and DDS. The combination of the voltage controlled oscillator and fractional-N synthesizer is perpetually locked. The fractional-N synthesizer is maintained in a locked condition. The VCO output is provided to the DDS. An output from the DDS or from the fractional-N synthesizer forms the output signal of the frequency generation unit.

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: During operation of a secondary communication system, nodes having different channel monitoring capabilities or requirements will cooperatively monitor possible frequencies for transmissions, each node using only a subset of all possible modulation sensing schemes. All nodes will share channel occupancy information to other nodes within the communication system. For example, a first group of nodes may monitor possible frequencies for television transmissions, while a second group of nodes may monitor the possible frequencies for APCO 25 transmissions. A group of nodes may also cooperatively monitor possible frequencies for more than one type of modulation transmission. Channel information will be shared among the nodes.

Abstract: The radio frequency (RF) environment is scanned and analyzed prior to entering a building or otherwise non-ideal propagation path environment. Upon entering the building or non-ideal propagation path environment, the mobile unit will scan the RF environment from within the building. An attenuation factor is determined for various frequencies. A channel then chosen to operate on in the cognitive system based on the attenuations of the various frequencies.

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: In a cognitive radio, a method of establishing an operational policy for use in a Peer-to-Peer (P2P) group, wherein the policy can be described by layers of policy parameters with progressively higher layers having a progressively increasing number of parameters, involves determining that a policy change is to be made from a current policy; requesting policy information from at least one P2P group member; receiving a policy description from the at least one P2P group member; and implementing a change in the lowest layer policy parameter to establish a new operational policy.

Abstract: A communications system and method for exchanging spectrum usage information through a drop box (100) includes one or more central stations (101) that defines a region of operation. A central drop box (102) is associated with the central station (101) for providing a database of spectrum usage information. Stations (103, 105, 107) using the communications system may submit information regarding spectrum usage to the central drop box (102) that affects the region of operation (109, 115) for providing the most efficient and non-interfering uses of the frequency spectrum.

Abstract: A cognitive radio (CR) device (208 and/or 218) avoids interference with an incumbent (207) receiver by determining maximum allowed transmit power levels of the CR device based on estimates of the incumbent signal level and transmit splatter levels of the CR device. The CR device (208 and/or 218) avoids interference with the incumbent receiver while transmitting with maximum transmit power levels.

Abstract: In a cognitive radio, a method of establishing an operational policy for use in a Peer-to-Peer (P2P) group, wherein the policy can be described by layers of policy parameters with progressively higher layers having a progressively increasing number of parameters, involves determining that a policy change is to be made from a current policy; requesting policy information from at least one P2P group member; receiving a policy description from the at least one P2P group member; and implementing a change in the lowest layer policy parameter to establish a new operational policy.

Abstract: During operation of a secondary communication system, cells (106) are formed by a plurality of localized nodes (104) to alert other nodes within the cell of frequencies which must be protected or otherwise avoided. All nodes within the cell monitor a differing subset of all frequencies available, and share information with respect to acceptable and protected frequencies with each other via low-power, short-range communication. Each node then forms a list of available channels for communication, and chooses a single node to report this information back to controller.

Abstract: A method and apparatus for allocation of shared spectrum in a wireless communication system uses a radio frequency (RF) beacon signal that is transmitted between access points of the wireless communication system. The information content of the RF beacon signal includes an identifier of the access point that generated the signal, identifiers of clients of that access point; and identifiers of the communication channels assigned to those clients. The client identifier may include at least part of an Internet Protocol (IP) address of the client. Additionally the beacon signal may contain client attributes to enable negotiation of the sharing of available communication channels between access points and clients.