Abstract: Systems and methods for handling cancellation of a Passive Intermodulation (PIM) signal are provided. The network device has access to and controls one or more transmitters and one or more receivers. The network device applies a determined PIM model to a transmitted signal from each transmitter of the network device, to obtain a modelled signal. The PIM model comprises a forward path model for each transmitter to the PIM source, a common non-linear model of the PIM signal from the PIM source being applied to a combined signal comprising the signals from each transmitter modelled by the forward path model, and a linear reflective path model from the PIM source to each of the receivers of the network device for a received PIM signal. The network device further subtracts the modelled signal from a received signal on each of the receivers of the network device.

Abstract: The present invention relates to method and arrangement in cellular mobile communication systems, in particular for handling of a physical random access channel for example in a Long Term Evolution communication network. By sending to at least one user equipment, UE, in a communication network cell an un-solicited speculative random access response, RAR, message comprising information relating to at least one of pre-amble identifier, allocated UE identifier, and uplink resource allocation data for L2/L3 message, it is possible to reduce the complexity of the access node, e.g. an eNodeB.

Abstract: A quadrature mixer arrangement is disclosed, which is adapted to translate an input signal by a translation frequency. The mixer arrangement is operated at a clock rate that equals the translation frequency times an oversampling rate, wherein the oversampling rate is not a multiple of four. The mixer arrangement comprises a sequence generator, at least one pair of mixers, and one or more correction networks. The sequence generator generates an in-phase mixer translation sequence and a quadrature-phase mixer translation sequence based on the oversampling rate. The in-phase mixer translation sequence is a time-discrete representation of a translation frequency sinusoidal function sampled at the clock rate, and the quadrature-phase mixer translation sequence is a time-discrete representation of the translation frequency sinusoidal function phase-shifted by ?/2 plus a phase deviation and sampled at the clock rate, wherein the phase deviation is a function of the oversampling rate.

Abstract: A quadrature mixer arrangement is disclosed, which is adapted to translate an input signal by a translation frequency. The mixer arrangement is operated at a clock rate that equals the translation frequency times an oversampling rate, wherein the oversampling rate is not a multiple of four. The mixer arrangement comprises a sequence generator, at least one pair of mixers, and one or more correction networks. The sequence generator generates an in-phase mixer translation sequence and a quadrature-phase mixer translation sequence based on the oversampling rate. The in-phase mixer translation sequence is a time-discrete representation of a translation frequency sinusoidal function sampled at the clock rate, and the quadrature-phase mixer translation sequence is a time-discrete representation of the translation frequency sinusoidal function phase-shifted by ?/2 plus a phase deviation and sampled at the clock rate, wherein the phase deviation is a function of the oversampling rate.

Abstract: A mixer unit (30) for frequency translating, based on an LO signal, an input signal having one or more input signal components is disclosed. The mixer unit has a signal processing path (50a-d, 60a-d) from each Input terminal (32+, 32?) to each output terminal (34_I+, 34_I?, 34_Q+,34_Q?) of the mixer unit (30), The LO signal has an associated LO signal component (LO_Ia-d, LO_Qa-d) for each signal processing path. The mixer unit (30) comprises a plurality of mixer switches (70a-N) and a control unit (90). The control unit (90) is adapted to, for each signal processing path (50a-d, 60a-d), dynamically select an associated subset, in the following denoted active switch subset, of the plurality of mixer switches (70a-N) for operation in the signal processing path (50a-d, 60a˜d) such that which of the plurality of mixer switches (70a-N) belong to said active switch subset varies in time.

Abstract: A technique for calibrating a receiver apparatus comprising at least one analog signal processing component and an intermediate frequency, or IF, mixer for converting IF signals comprising an in-phase, or I, signal and a quadrature-phase, or Q, signal to baseband frequency signals is provided. The IF mixer is arranged downstream of the at least one analog signal processing component. A method implementation of the technique comprises the steps of determining, in a digital processing domain downstream of the IF mixer, a metric which is affected by a frequency dependency of an imbalance between I and the Q signal, or IQ-imbalance, over a signal bandwidth, generating, based on the metric thus determined, a calibration signal configured to at least partially compensate a frequency-dependency of the IQ imbalance, and feeding the calibration signal to the at least one analog signal processing component so as to calibrate the at least one analog signal processing component.

Abstract: A receiver is operated so as to receive data conveyed on an Orthogonal Frequency Division Multiplexed (OFDM) signal transmitted on a plurality of sub-carriers. Such operation includes ascertaining which of the plurality of sub-carriers have a channel quality that satisfies one or more criteria. Then, sub-carriers are selected based at least in part on whether they have the channel quality that satisfies one or more criteria. The receiver then fully processes data streams only from the selected sub-carriers, wherein fully processing data streams comprises sub-carrier channel estimation or sub-carrier equalization or both sub-carrier channel estimation and sub-carrier equalization.

Abstract: A test signal for determining a frequency-dependent or any other property of a receiver path is proposed. The test signal comprises, in a time domain representation, a sequence of discrete states that may be periodically repeated and that gives rise to a plurality of discrete tones in a frequency domain representation of the test signal. The test signal can be utilized for determining a frequency-dependent imbalance (e.g., an IQ imbalance) between different signal branches of a receiver or transmitter.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

Abstract: The present invention relates to method and arrangement in cellular mobile communication systems, in particular for handling of a physical random access channel for example in a Long Term Evolution communication network. By sending to at least one user equipment, UE, in a communication network cell an un-solicited speculative random access response, RAR, message comprising information relating to at least one of pre-amble identifier, allocated UE identifier, and uplink resource allocation data for L2/L3 message, it is possible to reduce the complexity of the access node, e.g. an eNodeB.

Abstract: A mixer unit (30) for frequency translating, based on an LO signal, an input signal having one or more input signal components is disclosed. The mixer unit has a signal processing path (50a-d, 60a-d) from each Input terminal (32+, 32?) to each output terminal (34_I+, 34_I?, 34_Q+,34_Q?) of the mixer unit (30), The LO signal has an associated LO signal component (LO_Ia-d, LO_Qa-d) for each signal processing path. The mixer unit (30) comprises a plurality of mixer switches (70a-N) and a control unit (90). The control unit (90) is adapted to, for each signal processing path (50a-d, 60a-d), dynamically select an associated subset, in the following denoted active switch subset, of the plurality of mixer switches (70a-N) for operation in the signal processing path (50a-d, 60a˜d) such that which of the plurality of mixer switches (70a-N) belong to said active switch subset varies in time.

Abstract: A technique for calibrating a receiver apparatus comprising at least one analog signal processing component and an intermediate frequency, or IF, mixer for converting IF signals comprising an in-phase, or I, signal and a quadrature-phase, or Q, signal to baseband frequency signals is provided. The IF mixer is arranged downstream of the at least one analog signal processing component. A method implementation of the technique comprises the steps of determining, in a digital processing domain downstream of the IF mixer, a metric which is affected by a frequency dependency of an imbalance between I and the Q signal, or IQ-imbalance, over a signal bandwidth, generating, based on the metric thus determined, a calibration signal configured to at least partially compensate a frequency-dependency of the IQ imbalance, and feeding the calibration signal to the at least one analog signal processing component so as to calibrate the at least one analog signal processing component.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

Abstract: Digital IQ imbalance estimation and compensation is facilitated by shaping the frequency response of receiver branches. In particular, in a multi-carrier receiver, the frequency response of signal processing elements in at least one receiver branch is set to not fully attenuate received signals in a frequency band of interest. The frequency band of interest is greater than the carrier bandwidth of the received signal processed by that receiver branch. In some embodiments, the received signal is not attenuated, and adjacent interfering signals are partially attenuated. This allows information regarding the interfering signals to appear in an IQ imbalance-induced, inter-carrier image of the signals in anther receiver branch, facilitating digital estimation and compensation of IQ imbalance.

Abstract: A test signal for determining a frequency-dependent or any other property of a receiver path is proposed. The test signal comprises, in a time domain representation, a sequence of discrete states that may be periodically repeated and that gives rise to a plurality of discrete tones in a frequency domain representation of the test signal. The test signal can be utilized for determining a frequency-dependent imbalance (e.g., an IQ imbalance) between different signal branches of a receiver or transmitter.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described.

Abstract: The invention proposes a way of inserting an analog test signal during normal reception into analog blocks of an OFDM receiver in such a way that the reception is either not corrupted at all, or only very little. This is achieved either by inserting the analog test signal in time or frequency where it does not corrupt the received signal, or by accounting for the interfering analog test signal in the decoding process.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described.