Abstract: A location of at least one PIM source within an antenna array assembly is determined by applying an excitation waveform to a connection port, setting a multi-element phase shifter to a first state to apply a respective phase shift to respective paths, and making a first measurement of at least the phase of a PIM product emitted from the connection port. The multi-element phase shifter is then set to a succession of further states and further such measurements are made for each of the further states. From the first and further measurements a dependence is determined of at least the phase of the PIM product on the state of the multi-element phase shifter. The determined dependence is compared with a plurality of predetermined dependences, each predetermined dependence being for a PIM source located in a respective path between the multi-element phase shifter and a respective sub-array to determine the location within the antenna array assembly of the at least one PIM source.

Abstract: A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprise an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set.

Abstract: A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprise an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set.

Abstract: Methods and apparatus are disclosed for processing interference due to passive non-linear products of transmitted signals in a wireless network, and more specifically, but not exclusively, to reduction of interference caused to a receiver due to passive intermodulation (PIM) products generated from at least a first Multiple Input Multiple Output (MIMO) signal comprising first and second MIMO component streams at a first carrier frequency. In other scenarios, there may be two or more carrier frequencies combining to cause PIM, and each carrier frequency may have two or more MIMO component streams.

Abstract: A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set.

Abstract: A location is identified of at least one PIM (passive intermodulation) source in a frequency selective device by applying an excitation waveform to the frequency selective device and measuring a PIM response signature of the frequency selective device. The PIM response signature is a characteristic of PIM produced in response to the excitation waveform. The measured PIM response signature is compared with each of a plurality of example PIM response signatures, each of the plurality of example PIM response signatures corresponding to a characteristic of PIM expected for a respective location of a PIM source in the frequency selective device. The location of the at least one PIM source within the frequency selective device is determined on the basis of the comparison.

Abstract: Methods and apparatus are disclosed for processing interference due to passive non-linear products of transmitted signals in a wireless network, and more specifically, but not exclusively, to reduction of interference caused to a receiver due to passive intermodulation (PIM) products generated from at least a first Multiple Input Multiple Output (MIMO) signal comprising first and second MIMO component streams at a first carrier frequency. In other scenarios, there may be two or more carrier frequencies combining to cause PIM, and each carrier frequency may have two or more MIMO component streams.

Abstract: Interference (I1, I2) is mitigated in a waveform received at the input of a receiver in a wireless network, the interference comprising passive intermodulation PIM products of at least a first signal (C1). A first stream of time samples (5) is generated of a simulated first PFM product of at least the first signal (C1), and a second stream of time samples (6) is generated of the simulated first PIM product. The second stream has a delay with respect to the first stream. A replica (8) is generated of the interference by processing (7) at least the first stream and the second stream, the processing comprising reducing a degree of correlation between the first stream and the second stream, and the replica of the interference is combined with a stream of time samples of the received waveform (40) to reduce the interference in the received waveform.

Abstract: A location is identified of at least one PIM (passive intermodulation) source in a frequency selective device by applying an excitation waveform to the frequency selective device and measuring a PIM response signature of the frequency selective device. The PIM response signature is a characteristic of PIM produced in response to the excitation waveform. The measured PIM response signature is compared with each of a plurality of example PIM response signatures, each of the plurality of example PIM response signatures corresponding to a characteristic of PIM expected for a respective location of a PIM source in the frequency selective device. The location of the at least one PIM source within the frequency selective device is determined on the basis of the comparison.

Abstract: A PIM (passive intermodulation) diagnosis is generated for one or more wireless networks which have equipment deployed at a plurality of cell sites. Data is received representing PIM detection results from PIM detection devices at the cell sites, the detected PIM including PIM caused by passive intermodulation between carriers of the one or more wireless networks. The data representing respective PIM detection results is normalized to account for transmission power and frequency allocation of respective cell sites, and the normalized data representing respective PIM detection results is correlated with data relating to a condition of respective cell sites and/or an environment of the respective cell sites to produce correlation results. The PIM diagnosis is generated in dependence on the correlation results.

Abstract: Interference to a received signal is reduced in a wireless network, the interference comprising intermodulation products of at least a first signal and a second signal. Delayed interference signals comprising simulated intermodulation products are generated on the basis of the first signal and the second signal using a range of differing delay values and each of the delayed interference signals is correlated with the received signal to produce data representing a correlation for each delayed interference signal. At least one delay value is selected in dependence on a the data representative of the correlations and an interference signal comprising simulated intermodulation products generated from the first signal and the second signal using the at least one delay value is combined with the received signal.

Abstract: A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set.

Abstract: Interference is processed in a waveform received at a device in a wireless network, the received interference comprising non-linear products of at least a first signal (C1) at a first carrier frequency and a second signal (C2) at a second carrier frequency. A complex composite baseband signal is generated comprising at least the first and second signal at baseband, occupying a respective first and second frequency range within a composite baseband frequency range and not overlapping in frequency. The complex composite baseband signal is processed by applying at least a first non-linear function (74a) to generate simulated interference comprising at least one simulated non-linear product. The received interference is then processed in dependence on the simulated interference.

Abstract: Interference (I1, I2) is mitigated in a waveform received at the input of a receiver in a wireless network, the interference comprising passive intermodulation PIM products of at least a first signal (C1). A first stream of time samples (5) is generated of a simulated first PFM product of at least the first signal (C1), and a second stream of time samples (6) is generated of the simulated first PIM product. The second stream has a delay with respect to the first stream. A replica (8) is generated of the interference by processing (7) at least the first stream and the second stream, the processing comprising reducing a degree of correlation between the first stream and the second stream, and the replica of the interference is combined with a stream of time samples of the received waveform (40) to reduce the interference in the received waveform.

Abstract: Interference (I3) in a waveform received at a device in a wireless network is processed, the processing, for example, being used to detect and/or reduce the interference. The interference comprises non-linear products of at least a first signal. On the basis of at least the first signal, a plurality of interference product streams are generated, each stream comprising a stream of time samples of a simulated non-linear product of at least the first signal. At least two of the plurality of interference product streams are processed to reduce a degree of correlation between said at least two interference product streams thereby producing at least two processed interference product streams, which are correlated with the received waveform to produce a plurality of respective correlation values. The interference is processed in dependence on the plurality of respective correlation values.

Abstract: Interference in a data stream carrying a plurality of uplink signals received in a wireless network is processed, the interference comprising a non-linear product (I3) of at least one downlink signal (C1) of the wireless network. The data stream carrying the plurality of uplink signals and at least a first data stream carrying a plurality of downlink signals is received, and data representing signals received at a first uplink carrier frequency is selected from the data stream carrying the plurality of uplink signals. Data representing signals at at least a first downlink carrier frequency is selected from at least the first data stream carrying the plurality of downlink signals. Interference is detected in the selected data representing signals received at the first uplink carrier frequency by correlation with a synthesized product generated from at least data representing signals at the first downlink carrier frequency.

Abstract: A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set.

Abstract: Interference to a received signal is reduced in a wireless network, the interference comprising intermodulation products of at least a first signal and a second signal. Delayed interference signals comprising simulated intermodulation products are generated on the basis of the first signal and the second signal using a range of differing delay values and each of the delayed interference signals is correlated with the received signal to produce data representing a correlation for each delayed interference signal. At least one delay value is selected in dependence on a the data representative of the correlations and an interference signal comprising simulated intermodulation products generated from the first signal and the second signal using the at least one delay value is combined with the received signal.

Abstract: The invention relates to a method and apparatus for determining whether two user equipments (UEs) in a wireless network can be co-scheduled by an uplink scheduler. The method includes the determination of orthogonality factors for each pair of equipments to be considered and, from the orthogonality factors, selecting UEs to be co-scheduled.

Abstract: The invention relates to a method and apparatus for determining whether two user equipments (UEs) in a wireless network can be co-scheduled by an uplink scheduler of a base station. The method includes: the determination of a steering vector for each of a plurality of user equipments to be considered; and, for each pair of the user equipments, the determination of a corresponding orthogonality factor based on the steering vectors of the user equipments comprising the pair. A pair of user equipments may be selected for co-scheduling based on the orthogonality factors. For example, a pair of user equipments may be co-scheduled if its orthogonality factor is below a threshold. As another example, a pair of user equipments that has the lowest of the orthogonality factors may be co-scheduled.