Abstract: A method and transmitter for determining voltage standing wave ratios, VSWR, of an antenna array having multiple subarrays, each subarray having two branches. According to one aspect, a method includes grouping the branches of the 5 antenna array to form a number of groups, each group being formed so that nearest branches in group are separated by at least one branch not in the group. For each group, the method includes combining reflected signals from the branches of the group to produce a first signal YREFL and combining forward signals from the 10 branches of the group to produce a second signal YFWD; calculating a reflected power PREFL and a forward power PFWD and calculating a VSWR for the group based on the reflected power PREFL and the forward power PFWD.

Abstract: According to one or more embodiments, a proximity radio frequency connector for electromagnetically coupling a first circuit board with a second circuit board is provided. The proximity radio frequency connector includes: a housing defining an exterior mounting surface and an interior void opposite the exterior mounting surface where the housing is mountable to the second circuit board and the housing is movable in a direction at least one of perpendicular and tangential to the second circuit board, a proximity circuit board mountable to the exterior mounting surface of the housing, and a coupling first transmission line for electromagnetically coupling a signal to the first circuit board when the first circuit board is proximate the proximity circuitry board.

Abstract: An antenna element comprises a housing having a base and a conducting plate, and a feeding element. The housing has a cavity formed between the base and the conducting plate. The conducting plate has a radiating slot with a length and a width that extends longitudinally along a first axis and a second axis, respectively. The radiating slot has a first and a second edge along the first axis. The feeding element has a feeding point, a feeding line, and a stub. The feeding line extends along the second axis of the conducting plate across the width of the radiating slot such that a first end of the feeding line is coupled with the feeding point on one side of the radiating slot, and a second end of the feeding line extends past the second edge, and the stub extends laterally of the feeding line.

Abstract: A method and transmitter for determining voltage standing wave ratios, VSWR, of an antenna array having multiple subarrays, each subarray having two branches. According to one aspect, a method includes grouping the branches of the 5 antenna array to form a number of groups, each group being formed so that nearest branches in group are separated by at least one branch not in the group. For each group, the method includes combining reflected signals from the branches of the group to produce a first signal YREFL and combining forward signals from the 10 branches of the group to produce a second signal YFWD; calculating a reflected power PREFL and a forward power PFWD and calculating a VSWR for the group based on the reflected power PREFL and the forward power PFWD.

Abstract: A method and apparatus for calibrating an antenna array are described. Input signals and feedback signals are received, where the feedback signal is a combination of the input signals as captured after having traversed transmit paths and prior to being transmitted at a plurality of sub-arrays. A first interference reduced feedback signals is determined. A current estimation of the impairment function is determined. A second interference reduced feedback signals based on the current estimation of the impairment function, the input signals and the feedback signal. Responsive to determining that the power of the second interference reduced feedback signal satisfies a selection criteria, the current estimation of the impairment function is caused to be used for each one of the plurality of transmit paths for calibration of the antenna array and removing distortion.

Abstract: An antenna element is described. The antenna element comprises a housing having a base and a conducting plate, and a feeding element. The housing has a cavity formed between the base and the conducting plate. The conducting plate has a radiating slot with a length and a width that extends longitudinally along a first axis and a second axis, respectively. The radiating slot has a first and a second edge along the first axis. The feeding element has a feeding point, a feeding line, and a stub. The feeding line extends along the second axis of the conducting plate across the width of the radiating slot such that a first end of the feeding line is coupled with the feeding point on one side of the radiating slot, and a second end of the feeding line extends past the second edge, and the stub extends laterally of the feeding line.

Abstract: A method and apparatus for calibrating an antenna array are described. Input signals and feedback signals are received, where the feedback signal is a combination of the input signals as captured after having traversed transmit paths and prior to being transmitted at a plurality of sub-arrays. A first interference reduced feedback signals is determined. A current estimation of the impairment function is determined. A second interference reduced feedback signals based on the current estimation of the impairment function, the input signals and the feedback signal. Responsive to determining that the power of the second interference reduced feedback signal satisfies a selection criteria, the current estimation of the impairment function is caused to be used for each one of the plurality of transmit paths for calibration of the antenna array and removing distortion.

Abstract: Systems and methods for providing random access in a cellular communications network are disclosed. In general, the cellular communications network is an Orthogonal Frequency Division Modulation (OFDM) based cellular communications network (e.g., a 3GPP LTE cellular communications network) or similar multi-subcarrier based cellular communications network. Random access is performed using a Physical Random Access Channel (PRACH) including subcarriers having a subcarrier frequency spacing that is equal to a subcarrier frequency spacing in one or more other channels of the uplink (e.g., a Physical Uplink Shared Channel (PUSCH)). As a result, the subcarriers in the PRACH are orthogonal to the subcarriers in the other channel(s) of the uplink, which in turn reduces, or substantially eliminates, interference between the PRACH subcarriers and the subcarriers of the other channel(s) of the uplink.

Abstract: A method and system for time domain calibration to compensate for signal phase impairment in transmit paths in a transmitter configured to drive an antenna array are disclosed. According to one aspect, a base station is configured to compensate for signal impairment in transmit paths feeding an array of antenna elements in which the compensation is performed in the time domain. The base station includes a combiner configured to combine signals output from the transmit paths to form a feedback signal. An impairment estimator is configured to receive the feedback signal and outbound traffic signals and to determine a phase compensation value for each impairment path. A multiplier is provided for each transmit path, the multipliers configured to multiply the outbound traffic signals by respective phase compensation values.

Abstract: A method and system for time domain calibration to compensate for signal phase impairment in transmit paths in a transmitter configured to drive an antenna array are disclosed. According to one aspect, a base station is configured to compensate for signal impairment in transmit paths feeding an array of antenna elements in which the compensation is performed in the time domain. The base station includes a combiner configured to combine signals output from the transmit paths to form a feedback signal. An impairment estimator is configured to receive the feedback signal and outbound traffic signals and to determine a phase compensation value for each impairment path. A multiplier is provided for each transmit path, the multipliers configured to multiply the outbound traffic signals by respective phase compensation values.

Abstract: Systems and methods for providing random access in a cellular communications network are disclosed. In general, the cellular communications network is an Orthogonal Frequency Division Modulation (OFDM) based cellular communications network (e.g., a 3GPP LTE cellular communications network) or similar multi-subcarrier based cellular communications network. Random access is performed using a Physical Random Access Channel (PRACH) including subcarriers having a subcarrier frequency spacing that is equal to a subcarrier frequency spacing in one or more other channels of the uplink (e.g., a Physical Uplink Shared Channel (PUSCH)). As a result, the subcarriers in the PRACH are orthogonal to the subcarriers in the other channel(s) of the uplink, which in turn reduces, or substantially eliminates, interference between the PRACH subcarriers and the subcarriers of the other channel(s) of the uplink.

Abstract: Systems and methods for providing random access in a cellular communications network are disclosed. In general, the cellular communications network is an Orthogonal Frequency Division Modulation (OFDM) based cellular communications network (e.g., a 3 GPP LTE cellular communications network) or similar multi-subcarrier based cellular communications network. Random access is performed using a Physical Random Access Channel (PRACH) including subcarriers having a subcarrier frequency spacing that is equal to a subcarrier frequency spacing in one or more other channels of the uplink (e.g., a Physical Uplink Shared Channel (PUSCH)). As a result, the subcarriers in the PRACH are orthogonal to the subcarriers in the other channel(s) of the uplink, which in turn reduces, or substantially eliminates, interference between the PRACH subcarriers and the subcarriers of the other channel(s) of the uplink.

Abstract: In some embodiments, a network node uses beam frames to broadcast acquisition information on a plurality of beam sets (N). Each beam sets includes a plurality of beams (K). The network node broadcasts the acquisition information one beam set at a time during a corresponding one of a periodic plurality (X) of the beam frames. The periodic plurality (X) of beam frames occur with a first periodicity and are within a periodic plurality (Y) of subframes occurring with a second periodicity.

Abstract: Embodiments of a hybrid unit that supports a configurable number of radio units for a base station in a cellular communications network and embodiments of Distributed Digitally Convertible Radio Units (DDCRUs) for use with the hybrid unit are disclosed. In one embodiment, a hybrid unit for a base station in a cellular communications network is provided. The hybrid unit includes an analog hybrid matrix. The analog hybrid matrix includes a number of feeder ports operative to connect to at least one radio unit and up to a number of radio units that are external to and separate from the hybrid unit. In one preferred embodiment, the radio unit(s) is(are) DDCRU(s). The analog hybrid matrix also includes a number of antenna ports operative to connect to at least one and up to a corresponding number of antennas of the base station.

Abstract: Embodiments of a system for a multi-sector base station in a cellular communications network are disclosed. In one embodiment, the system includes an integrated unit, where the integrated unit includes multiple antennas and a radio unit (RU) coupled to the antennas. By integrating the multiple antennas and the radio RU into a single integrated unit, the system can, in some embodiments, reduce installation and operating costs of the multi-sector base station.

Abstract: Systems and methods for providing random access in a cellular communications network are disclosed. In general, the cellular communications network is an Orthogonal Frequency Division Modulation (OFDM) based cellular communications network (e.g., a 3GPP LTE cellular communications network) or similar multi-subcarrier based cellular communications network. Random access is performed using a Physical Random Access Channel (PRACH) including subcarriers having a subcarrier frequency spacing that is equal to a subcarrier frequency spacing in one or more other channels of the uplink (e.g., a Physical Uplink Shared Channel (PUSCH)). As a result, the subcarriers in the PRACH are orthogonal to the subcarriers in the other channel(s) of the uplink, which in turn reduces, or substantially eliminates, interference between the PRACH subcarriers and the subcarriers of the other channel(s) of the uplink.

Abstract: In some embodiments, a network node uses beam frames to broadcast acquisition information on a plurality of beam sets (N). Each beam sets includes a plurality of beams (K). The network node broadcasts the acquisition information one beam set at a time during a corresponding one of a periodic plurality (X) of the beam frames. The periodic plurality (X) of beam frames occur with a first periodicity and are within a periodic plurality (Y) of subframes occurring with a second periodicity.

Abstract: A calibration method for a base station removes distortion in traffic signals incurred in transmit paths of the base station. The transmit paths are coupled to an antenna array for transmitting the traffic signals in a wireless network. The method includes conditioning a traffic signal to reduce a correlation with another traffic signal before the traffic signals enter the transmit paths. For each of the traffic signals, an impairment estimation is performed based on the traffic signals captured before entering the transmit paths and the traffic signals captured before entering the antenna array. An approximate inverse of the impairment estimation is applied to each of the traffic signals before the traffic signals enter the transmit paths.

Abstract: Embodiments of a system for a multi-sector base station in a cellular communications network are disclosed. In one embodiment, the system includes an integrated unit, where the integrated unit includes multiple antennas and a radio unit (RU) coupled to the antennas. By integrating the multiple antennas and the radio RU into a single integrated unit, the system can, in some embodiments, reduce installation and operating costs of the multi-sector base station.

Abstract: Methods and devices for extracting a RACH preamble using as input a number of Fast Fourier Transformed symbols, in order to extract a random access channel (RACH) preamble from a signal received in a base station from a user device, in a radio communication system, are provided. An initial cyclic prefix (symbol CP) is removed prior to performing FFT on symbols. After (1) selecting from the FFT of a symbol frequencies corresponding to the RACH band all other non-RACH frequency bins having been set to zero, (2) shifting the signal to baseband and (3) performing a FFT on the baseband signal, a phase adjustment is performed to compensate for group delays due to symbol CP gaps occurring when generating the baseband signal, the phase adjustment being determined individually for each symbol.