Abstract: Methods and systems can provide accurate synchronization of two nodes even when those nodes cannot communicate directly with one another. A method, for example, can include determining a first propagation delay estimate to a first node (910). The method can also include determining a second propagation delay estimate to a second node (920). The method can further include receiving a first synchronization message from the first node (930). The method can additionally include transmitting a second synchronization message to the second node (940). The second synchronization message depends on the first synchronization message, the first propagation delay estimate, and the second propagation delay estimate.

Abstract: Methods and apparatuses are disclosed that provide flexible use of a shared radio resource. An apparatus determines from monitoring signal energy on a shared radio resource whether other transmitters are present. A predetermined set of time division duplex (TDD) signaling patterns are identified. A correlation is performed between signal energy received on the shared radio resource and the predetermined TDD signaling patterns. The apparatus may then determine a TDD signaling pattern that may reduce or avoid interference with any other transmitters using the shared resource. The shared radio resource may be, for example, a shared frequency spectrum. Efficient allocation of radio resources among apparatuses such as radio transceivers, without fixed time references or predetermined patterns, may be obtained. The radio transceivers may be base stations or mobile user equipment in a wireless communications system. The apparatus may be an integrated circuit, a portion thereof, or chipset.

Abstract: A method for interference-aware scheduling is provided. The method can include acquiring a plurality of interference characteristics, each of the interference characteristics associated with a range of communication resources. The method may further include combining at least two of the interference characteristics into a combined interference characteristic, and transmitting a message encoding the combined interference characteristic.

Abstract: In accordance with an example embodiment of the present invention, an apparatus comprises a transceiver configured to receive a transmission from a radio node, the transmission including a synchronization signal; a processor configured to determine a state of synchronization with the radio node and based at least in part on the state of synchronization adjusting at least one transmission parameter.

Abstract: A method, apparatus and computer program product are configured to provide calibration accuracy in an analog filter. In this regard, a method is provided that includes estimating a cutoff frequency for an analog filter. The method further includes causing a filter tuning word to be modified based on the estimated cutoff frequency for the analog filter. The method also includes determining a residual cutoff frequency mismatch for the analog filter. The method also includes causing an equalizer configuration to be selected for a digital filter based on the determined residual cutoff frequency mismatch.

Abstract: The present invention introduces a method, an apparatus and a computer program product for mitigating effects of alias responses in a transceiver, by selecting a clock rate for an analog-to-digital converter based on a determined maximum conversion rate of the ADC. The selected conversion rate places an alias response of the unwanted signal component to a frequency range which is substantially non-overlapping with a wanted signal component of the receiver. Furthermore, a temperature of the transceiver may be measured e.g. by a temperature compensation unit of a reference oscillator. Furthermore, a data table may be used by a processing unit for linking temperatures with maximum conversion rates of the analog-to-digital converter. The method is implemented in the processing unit of the transceiver which is further configured to execute the operations of the corresponding computer program product according to the invention.

Abstract: Usefulness of resource usage sensing information is determined by at least one node in a radio system. Transmission of sensing result information in the radio system is then controlled based at least in part on the determined usefulness.

Abstract: An apparatus, system and method for providing interference cancellation and communication resource reservation limits to allocate communication resources in a communication system. In one embodiment, the apparatus includes a processor (1320) and memory (1350) including computer program code. The memory (1350) and the computer program code are configured, with the processor (1320), to cause the apparatus to identify an interval of received signal power levels for interference cancellation of an interfering signal to a primary signal, and generate a message that provides the interval of received signal power levels for the interference cancellation of the interfering signal to the primary signal. In a related embodiment, the memory (1350) and the computer program code are configured, with the processor (1320), to cause the apparatus to determine a communication resource reservation limit, and request an increase in the communication resource reservation limit.

Abstract: The present invention presents a method and a system for mitigating effects of clock harmonics in the receiver. The receiving signal may be monitored in such a way that the interfering harmonic component is tracked. When the interfering frequency is found out, the system determines the clock or clocks in the transceiver which are contributing to the interfering spurious tone. After that, the contributing clock(s) frequency is selected so that the effect of the spurious tone in the receiving passband is minimized or mitigated. This is performed by selecting a suitable clock frequency resulting in the spurious tones all falling outside the receiver passband; or in an OFDM system, by choosing a clock frequency deriving the spurious tone straight onto a subcarrier signal frequency.

Abstract: In a non-limiting and exemplary embodiment, a method is provided for adapting a device set of one or more radio devices providing detection estimates for the presence of a primary radio resource user. A first detection estimate for the presence of the user is determined on the basis of spectrum sensing. At least one other detection estimate for the presence of the user is received from the device set. A detection value is generated on the basis of the first detection estimate and the at least one other detection estimate, and the device set is adapted on the basis of the detection value.

Abstract: A method, apparatus, system, and computer program product example embodiments of the invention are disclosed to structure access to a wireless medium to reduce interference between nearby nodes. In example embodiments of the invention, a method includes the steps of determining an amount of available wireless communication resources in a reception area; determining a number of wireless communication nodes in the reception area; generating a reservation limit of the available wireless resources; determining an inability to allocate the reservation limit of the available wireless resources; transmitting a request for release of resources to at least one other wireless communication node. Another node receiving the request, performs a method including the steps of determining a threshold; comparing an allocated amount of wireless communication resources against the threshold; and releasing at least a part of the allocated amount of resources, if the reserved number is greater than the threshold.

Abstract: An apparatus includes a controller configured to be coupled with a radio interface of a first wireless network node. The controller is further configured to respond to a spectrum emission mask that includes indications of both desirable emissions and undesirable emissions over a plurality of radio resource allocation units and to estimate a signal to noise ratio in individual ones of radio resource allocation units at at least one second node, to select an appropriate modulation-and-coding scheme per radio resource allocation unit and to schedule transmissions for the radio interface on the radio resource allocation units using the selected modulation-and-coding scheme. The controller is further configured to receive via the radio interface a beacon transmission from a second node, where the beacon transmission indicates a receiver sensitivity of the second node.

Abstract: Systems and techniques for equalization of a response of a receiver. In one embodiment, a response of a device to a known signal is measured to generate a measured signal. A processor is operated to apply an initial weighting to the measured signal and the known signal. The processor is operated to iteratively perform the operations of constructing an equalizer based on the weighted signals, testing the performance of the equalizer on the measured signal, and adjusting weighting applied to the measured signal and the known signal, until the performance of the equalizer on the measured signal meets a predetermined criterion.

Abstract: A method, an apparatus, and a computer program for performing cognitive communications in a radio environment are presented. First, a radio communication device estimates a time-varying interference environment in a radio communication channel. On the basis of the estimation, a future interference environment is predicted from time-varying characteristics of the estimated interference. Upon predicting the future interference environment, a radio transmitter is configured to apply transmission parameters to be used in a future transmission time instant for which the interference environment has been predicted. As a consequence, the transmission parameters are selected proactively to match with the predicted interference environment. The transmission parameters may be configured as time-variant.

Abstract: An apparatus, method and system for reducing discontinuities between waveforms in a communication system. In one embodiment, an apparatus includes a processor and memory including computer program code. The memory and the computer program code are configured, with the processor, to determine an amplitude and set of derivatives at an end point of a first symbol waveform, and determine an amplitude and set of derivatives at a beginning point of a second symbol waveform. The memory and the computer program code are configured, with the processor, to insert a guard period waveform having an amplitude and set of derivatives at a first end to substantially match the amplitude and set of derivatives at the end point of the first symbol waveform and an amplitude and set of derivatives at a second end that substantially matches the amplitude and set of derivatives at the beginning point of the second symbol waveform.

Abstract: Apparatus includes an equalizer having a signal input, a control input and an output; a controllable power supply having a control input and an output, the input of the controllable power supply being coupled to the output of the equalizer; a power amplifier having a main signal input, a power supply input, and an output, the power supply input being coupled to the output of the controllable power supply; and a controller having first and second inputs and an output, the first input being coupled directly or indirectly to the output of the controllable power supply, the second input being coupled to a node upstream of the equalizer, and the output being coupled to the control input of the equalizer; the equalizer being configured to apply equalization to an envelope signal received at its input and to provide a resulting equalized envelope signal at its output, the controllable power supply being configured to provide a power signal at its output based on the equalized envelope signal received at its input, t

Abstract: In one aspect of the exemplary embodiments of this invention a method includes determining, based at least in part on a number of resource blocks to be transmitted, where the resource blocks may be spectrally contiguous or spectrally non-contiguous, a ratio of power to be provided by a switched mode power supply to power to be provided by a linear mode power supply; controlling the switched mode power supply and the linear mode power supply in accordance with the determined ratio to supply a total amount of power and providing the total amount of power to a supply voltage input of a polar transmitter.

Abstract: A method for unsynchronized signaling between nodes in a network is described. The method includes partitioning a message for asynchronous transmission in a network into a plurality of symbols. A symbol includes a cyclic prefix. Causing the plurality of symbols to be transmitted (for example, via a transmitter) on one or more subcarriers allocated for asynchronous transmissions is also included in the method. A given symbol is transmitted so as to reduce a discontinuity between a previous symbol and the given symbol. The method may also include applying a phase shift to one or more symbols of the plurality of symbols. Transmitting may include transmitting at a transmission frequency, where a length of a transmission cycle is determined by the transmission frequency, and where a length of the cyclic prefix is equal to an integer number of transmission cycles. Apparatus and computer readable media are also described.

Abstract: In accordance with an example embodiment of the present invention, a method comprises receiving a input signal comprising an interfering signal component and a desired signal component at a wireless device; estimating a frequency error of the interfering signal component; and frequency-shifting the input signal based at least in part on the estimated frequency error. The method also comprises estimating a frequency response based on the frequency-shifted input signal and a reconstructed first cancellation signal; obtaining a second cancellation signal by applying the estimated frequency response to the first cancelation signal; subtracting the second cancellation signal from the input signal; and decoding the desired signal component from the input signal after the second cancellation signal is subtracted from the input signal.

Abstract: The present invention relates to a method for using the peak-to-average power ratio (PAR) of signals received by a receiver to control the gain of the receiver for an analogue-to-digital converter (ADC) and/or to control the dynamic range of the ADC.