An equalizer that has a wide variable gain range and that can implement equalization for a communication medium such as on-board wiring or a cable having various wiring lengths. The equalizer includes a core circuit and a source follower connected to a subsequent stage of the core circuit. The core circuit includes a differential pair including a first transistor and a second transistor, and a zero point generation circuit connected between a second terminal of the first transistor and a second terminal of the second transistor. The source follower includes a third transistor and a fourth transistor, a variable bias current source is connected to the third and fourth transistors, and a load in which a capacitive element and a resistor element are connected in series via a switching element is connected to wiring that connects the third and fourth transistors to an output terminal.

A reception apparatus includes reception circuitry and decoding circuitry. The reception receives a signal including a legacy header field, an enhanced directional multi-gigabit (EDMG) header field, and a data field. The decoding circuitry decodes data included in the data field of the received signal. The legacy header field includes a Length field comprising multiple bits. The reception apparatus is an EDMG terminal, and a subset of the multiple bits of the Length field included in the legacy header field is used to indicate bandwidth over which the signal is transmitted. Remaining bits of the Length field included in the legacy header field are used to indicate data length of the received signal.

Embodiments relate to apparatuses (10; 20), methods and computer programs for determining transmission control information. The Apparatus (10) is suitable for a base band unit (110) of a base station transceiver (100) of a mobile communication system (300), the base station transceiver (100) further comprising one or more radio units (120) configured to wirelessly communicate with the base band unit (110) using one or more wireless fronthaul links. The apparatus (10) comprises at least one output (12) configured to transmit a downlink component of the one or more wireless fronthaul links to the one or more radio units (120). The apparatus (10) further comprises at least one input (14) configured to receive an uplink component of the one or more wireless fronthaul links from the one or more radio units (120). The apparatus (10) further comprises a control module (16) configured to control the at least one output (12) and the at least one input (14). The control module (16) is further configured to transmit a reference signal via the at least one output (12) to the one or more radio units (120). The control module (16) is further configured to receive a loopback version of the reference signal via the at least one input (14) from the one or more radio units (120). The control module (16) is further configured to determine transmission control information based on an attenuation of the reference signal determined based on the loopback version of the reference signal. The transmission control information comprises information related to a per-radio unit transmission power to be used by the one or more radio units (120) for transmissions on the one or more wireless fronthaul links. The control module (16) is further configured to provide the transmission control information to the one or more radio units (120) via the at least one output (12).

Multipoint broadcasting relying on channel reciprocity in a TDD network requires that the broadcasters be calibrated. In the cases where the relative amplitude profiles and nonlinear phases are time-invariant or slow-varying, broadcaster calibration reduces to phase synchronization. Methods and apparatus are described that provide broadcaster calibration and phase synchronization with terminal feedback and overcome the drawbacks of self-calibration. The methods and apparatus are capable of calibrating hundreds of broadcaster antennas in massive antenna applications while maintaining an extremely low overhead. Applications of the described methods and apparatus include multipoint broadcasting in wireless networks, also known as coordinated multipoint transmission, or CoMP, in LTE-A (long-term evolution, advanced) networks, and distributed MIMO, massive MIMO, massive beamforming, etc., in other networks including 5G and 802.11. Applications also include frequency and phase synchronization of a cluster of wireless devices.

Embodiments of the present invention relate to a signal sending method, a signal receiving method, a base station, and user equipment. The method includes: determining, by a base station based on receiver capabilities of user equipments, that first user equipment is to be paired with N second user equipments on a first resource block, where N is a positive integer; and multiplexing, by the base station, a signal of the first user equipment and signals of the N second user equipments onto the first resource block, and sending the signals. It can be learned from the foregoing that according to the embodiments of the present invention, not only channel quality of weak-receiver-capability user equipment is ensured, but also channel quality of strong-receiver-capability user equipment is maintained by using an excellent interference suppression capability of the strong-receiver-capability user equipment.

There are provided systems, methods, and interfaces for optimization of the fronthaul interface bandwidth for Radio Access Networks and Cloud Radio Access Networks.

Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

Various embodiments herein provide techniques for minimum mean-square error interference rejection combining (MMSE-IRC) processing of a received signal, distributed between a baseband unit (BBU) and a remote radio unit (RRU). The RRU may perform a first phase of processing based on an extended channel that includes a channel of one or more user equipments (UEs) served by the RRU and interference samples that correspond to other cells or additive noise. The first phase may include scaling the interference samples by a scaling coefficient to obtain a modified extended channel, and performing maximum ratio combining (MRC) on the modified extended channel to obtain a processed signal. The RRU may send the processed signal to the BBU for the second phase of processing. The second phase of processing may include regularized zero forcing to remove interference. Other embodiments may be described and claimed.

A receiver circuit comprising an averaging-processing-block that is configured to receive an OFDM signal. The OFDM signal comprises a plurality of sample-values, wherein the sample-values comprise: a middle-sample-value; a lower-sample-value-group; and a higher-sample-value-group. The averaging-processing-block can determine an averaged-sample-value for the middle-sample-value by performing an averaging operation on the sample-values of the lower-sample-value-group and the higher-sample-value-group, but not on the middle-sample-value.

Multipoint broadcasting relying on channel reciprocity in a TDD network requires that the broadcasters be calibrated. In the cases where the relative amplitude profiles and nonlinear phases are time-invariant or slow-varying, broadcaster calibration reduces to phase synchronization. Methods and apparatus are described that provide broadcaster calibration and phase synchronization with terminal feedback and overcome the drawbacks of self-calibration. The methods and apparatus are capable of calibrating hundreds of broadcaster antennas in massive antenna applications while maintaining an extremely low overhead. Applications of the described methods and apparatus include multipoint broadcasting in wireless networks, also known as coordinated multipoint transmission, or CoMP, in LTE-A (long-term evolution, advanced) networks, and distributed MIMO, massive MIMO, massive beamforming, etc., in other networks including 5G and 802.11. Applications also include frequency and phase synchronization of a cluster of wireless devices.