Abstract: A method for minimizing message collision in a device is presented. Two or more overlapping real-time streaming simplex audio messages are received. One of the audio messages is forwarded to be reproduced while the other is stored. Forwarding of the delayed audio message is delayed such that overlapping reproduction of the audio messages is minimized. Reproduction is delayed until a predetermined clock time expires or is dependent on one or more of: the length of the second audio message or the amount of overlap of the first and second audio messages.

Abstract: A method for minimizing undesired signal coupling from digital interface between peripherals is presented. The method includes transmitting over the interface first and second signals having a parameter ?k set by a dynamic sequencer respectively to a first and second value ?1 and ?2, receiving the first and second signal and generating a first and second interference metric respectively for the first and second signal. The first and second interference metrics are correlated to generate a final parameter value ?f, and a transmitter is then configured to transmit a third signal over the interface with the final parameter value ?f.

Abstract: A post-mixer amplifier device which receives and processes signals for use in a software-defined radio integrated circuit is provided. The post-mixer amplifier device includes but is not limited to a voltage amplifier having first and second inputs and a first output, a positive signal output connected with the first output of the voltage amplifier, and a positive signal input connected with a first bipolar junction transistor along a first pathway. The first bipolar junction transistor includes but is not limited to a first collector connected with a the first input of the voltage amplifier and a first emitter connected with an second output of the push-pull unity gain follower and forming a first current feedback pathway. The first bipolar junction transistor is driven with a passive resistive load.

Abstract: An apparatus and method for receiving and processing multiple independent, uncorrelated RF signals is presented. The apparatus includes a Hybrid-Direct Conversion Receiver incorporating front end branches, protocol-specific digital processing branches, an interference detector, a correlator, and an offset control for controlling oscillator sources. The front end branches each contain a preselector that filters received signals and a mixer that down converts the received signal to an IF offset from a reference frequency by a unique offset. The bandwidth of an IF processor is partitioned into sub-channels corresponding to the different offsets and is wider than the combination of the sub-channels. The interference detector and correlator determine whether a particular desired signal is degraded by interference signals and select a new sub-channel. This information is provided to the offset control, which adjusts a LO source coupled to the corresponding down mixer accordingly.

Abstract: A method and apparatus is disclosed for increasing calling capacity in a carrier using enhanced Terrestrial Trunk Radio (TETRA) protocols. The method includes transmitting, by a base station to at least one mobile station, a permission signal for an assigned timeslot on a carrier, wherein each timeslot is divided into at least two sub-slots. The method also includes configuring a control signal that is associated with each of the plurality of timeslots. Specific fields in the control signal are associated with each sub-slot on each of the plurality of timeslots. The method further includes providing usage markers through the control signal. Usage markers values are divided into ranges, each range used to identify a timeslot or a sub-slot assignment on the carrier. The base station sends a time advance value to the mobile station to indicate when transmission from the mobile station is to begin.

Abstract: Methods of enabling late entry into an on-going spread spectrum call are described. A late join frame replaces, and has the same size as, a traffic frame. A late join slot in the late join frame contains sufficient information in preamble and sync subframes to permit a target to join the call. The traffic slots in the late join frame replicate data such that call quality of the call is substantially unaffected if one of the remaining traffic frames is not received. The preamble and sync subframes frequencies may be the same as, or different from, preamble and sync frames frequencies during a call establishment phase of the call. If different, the preamble and sync subframes frequencies are selected from one or more frequencies. Use of the preamble and sync subframes frequencies is compensated for when selecting the traffic slot frequencies to obtain uniform utilization of the spectrum.

Abstract: A receiver and method of correcting for amplitude and phase errors in a received complex signal are provided. After separating and processing the complex signal into its I and Q component signals, the magnitude of each of the I and Q signals is obtained. The magnitudes are averaged over a predetermined time period and the average used to correct the amplitude of the I and Q signals. Each amplitude-corrected signal is then rotated by 45° and the average magnitude of the rotated signal determined. The amplitude of the rotated signal is then corrected to provide resultant I and Q signals, which are orthogonal to each other.

Abstract: An interference device and method of interfering with signals from a UMTS base station in a particular area are disclosed. The interference device receives a signal from the base station intended for a mobile device to initiate a communication session. The interference device synchronizes to the S-CCPCH and alters the TCFI and/or the data in the data field of the slot so that it is not longer correct. Time-shifted copies of the altered signal are then multiplexed and transmitted to the mobile device as a jamming signal. The jamming signal is received by the mobile device and causes the mobile device to be unable to determine the data of the original signal from the base station.

Abstract: A method of detecting an on-channel signal and synchronizing signal detection with correcting for DC offset errors in a direct conversion receiver is presented. A received signal is digitized, and a state machine operates to detect the presence of an on-channel signal. If the signal is not detected, a mixed mode training sequence is initiated in which the DC offset errors in both an analog and digital received signal path are corrected. While training, processing of the digitized samples by a digital signal processor and a host controller is suspended (while they are put into battery save mode) and the gain provided to subsequently received signals is minimized. The DC offset correction circuitry is bypassed and put into battery save mode at predetermined periods when DC offset correction is not performed.

Abstract: An electronic device (200) comprises a touch screen (210), a pen-form stylus (170) for activating the touch screen (210), and a receptacle (220) located within or coupled to the electronic device (200) for storage of the pen-form stylus (170). The electronic device (200) comprises a flexible attachment mechanism (130) that is fixed to both the pen-form stylus (120) and the electronic device (230). The stylus (170) comprises a slot (150) such that the flexible attachment mechanism (130) is located within the slot (150). In this manner, an efficient geometry of the electronic device prevents the stylus being misplaced and enables the flexible attachment mechanism (130) to be located within the slot by the action of inserting the stylus (170) into the receptacle (220).

Abstract: Communication nodes, acting as intermediate routers for communication packets transmitted between a source node and a destination node, are provided with different access rights to the fields of the routed communication packets. Routes of intermediate routers between the source node and the destination node are discovered and the identities of intermediate routers on the discovered routes are collected. The aggregate trust levels of the intermediate routers are computed allowing the most trusted route to be selected. Encryption keys are securely distributed to intermediate routers on the most trusted route based on the trust level of the intermediate routers and fields of the communication packets are encrypted with encryption keys corresponding to the assigned trust level. Intermediated nodes are thereby prevented from accessing selected fields of the communication packets.

Abstract: A communication device and method of removing an LO leakage signal from a signal path on the fly is disclosed. The signal path may be that of a transmitter or receiver. An initial RF output signal, containing a desired RF output signal and an LO leakage signal, is supplied from a feedforward path to a combiner/splitter on a feedback path. A 180° out-of-phase copy of the desired RF output signal is also supplied to the combiner/splitter. The resulting LO leakage signal is down-converted and the power of the down-converted signal determined and used to suppress the LO leakage signal. The resulting LO leakage signal is also supplied to the feedforward path of the feedback loop.

Abstract: A communication device having an RF power amplifier stage with a Cartesian feedback loop is provided. The loop has forward paths whose outputs are combined to form an output signal that is fed back to a single feedback path. Each forward path has a common path with a filter that filters the overall loop response and a unique split path. The main and auxiliary split paths have a power amplifier and carry signals respectively of lower and higher frequencies. The auxiliary amplifier is faster than the main amplifier. Different phases of the carrier signal are used during upconversion such that the overall phase response through the split paths is equal. Instability recovery problems introduced by higher-order loop filters are mitigated by baseband loop filters with switchable order. Upon detecting instability, the loop filter order is reduced and is subsequently increased after eliminating the unstable operation.

Abstract: A terminal (200) and method for operation thereof for use in a wireless communication system (100), the terminal including a plurality of antennas (215, 235, 255) and a plurality of receiver chains (217, 237, 257) each including an associated one of the antennas, the terminal being operable to receive a signal including a plurality of time divided portions including a first portion (303) and a second portion (304), characterized in that the terminal is operable in a manner such each of the plurality of receiver chains is active when the first portion of the signal is being received and at least one of the receiver chains is inactive when the second portion of the signal is being received.

Abstract: A method (1100, 1200) of generating a composite mitigation signal (216, 902, 1002) is presented. The composite mitigation signal includes an odd integer (N) of transitions (310, 312) between a first amplitude and a second amplitude of the composite mitigation signal. Successive sets of the transition bursts are separated by a desired phase delay or time delay (330), or such separations are defined by a base signal (416) having a frequency equal to a fundamental frequency of the composite mitigation signal. The composite signal generators (222, 900, 1000) that generate the composite mitigation signal are also presented.

Abstract: Free space antenna structures are presented in which multiple radiating elements are disposed proximate to each other. In a structure containing two radiating elements, the radiating element of shorter wavelength is split into a monopole and a dipole that are electrically, but not physically, coupled to each other. The monopole has a length of ?/4 and is attached to the same feed as the longer wavelength radiating element. The dipole has a length of ?/4 and is attached to the same feed as the longer wavelength radiating element. Non-conductive shields prevent contact between the monopole, dipole, and longer wavelength radiating element. The longer wavelength radiating element is formed in a helix outside of which the dipole, and perhaps monopole, is disposed.

Abstract: A method for synchronizing audio reproduction in collocated end devices is presented. Each of the devices auto-correlates using noise to determine a threshold prior to the antenna receiving an audio signal. When the devices receive a common audio signal, they provide audio outputs. Each device cross-correlates its audio output with the audio outputs of the other devices. The timing of the audio output of each device is then adjusted such that the audio outputs of all of the devices align temporally with the lagging or leading device.

Abstract: A device and method of modifying an image containing a foreground and an original or substitute background are disclosed. Boundary pixels contain only the original background or the original background and the foreground. The original background is replaced by a predetermined or random color or by a color corresponding to the substitute background. The entire boundary pixel can be replaced by the replacement color. Alternatively, the ratio of the foreground to the original background can be estimated from the neighboring pixels and only the original background replaced by the replacement color. Once some or all of the boundary pixels are replaced, the image can be transmitted or otherwise transferred to other devices or viewers. Some or all of the images in a video can be modified.

Abstract: A communication device and method are presented. The device is in a network of devices of different groups. The device contains a push-to-talk (PTT) button, a channel selector, and a keyboard containing hard or soft keys. The channel selector selects an initial frequency at which to receive and transmit, dependent on the group to which the device belongs. The device transmits when the PTT button is pressed. If a multiple PTT function is activated by software in the device, at least some of the keys are used to select a new transmission frequency. The device receives at the initial frequency independent of the transmission frequency. The multiple PTT function can be activated by a dedicated soft or hard key or a key on the keyboard that serves multiple functions. The frequency selection provided by the keys is dependent on the channel and the device group.

Abstract: Method and systems of improving the response of public safety personnel to or evacuation from a desired location are provided. In addition to path information obtained through traditional sources, information is used to determine the optimal route for emergency personnel to an emergency situation and for aiding emergency personnel to route people from the situation. The information may also be used to automatically prioritize vehicles and personnel to optimize response time. Further, the information may also be used to in situations in which it is advantageous for the vehicle or personnel to be tactically positioned in nearby locations rather than at the incident scene. Although the descriptions below will primarily focus on routes to a particular location, similar methods can be used for evacuations from the location. The optimal route may use historical information stored in a database local or remote to the dispatcher and/or real-time information updated during the emergency situation.