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.

This disclosure relates to techniques for performing ranging wireless communication in a secure manner. A first wireless device may receive a plurality of independent sequences from a second wireless device. The first wireless device may perform a combined channel estimate using the sequences. The first wireless device may estimate the distance (or angle/direction, among various possibilities) between the two devices based on the combined channel estimate.

A MIMO-OFDM system for increasing reliability includes a transmission terminal that includes N.sub.t transmission antennas and transmits a MIMO signal through relay terminals, and a reception terminal that receives the MIMO signal from the relay terminal through N.sub.r reception antennas, and the transmission terminal extracts a composite channel coefficient from a composite channel generated by matching a channel between the transmission terminal and the reception terminal with a channel between each of a plurality of the relay terminals and the reception terminal, selects the relay terminal corresponding to the composite channel coefficient having a maximized channel capacity from among the plurality of relay terminals by using the extracted composite channel coefficient, and transmits a MIMO signal to the reception terminal through the selected relay 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.

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.

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.

Embodiments of the present disclosure are related to system and method of classifying speed of at least one user equipment (UE). The method comprises receiving a plurality of input signals associated with the at least one UE. Also, method comprises estimating a plurality of channels using a plurality of reference signals associated with the inputs signals. Further, the method comprises computing a metric between the estimated plurality of channels and classifying speed of the at least one UE using the computed metric. The classifying the at least one UE using the metric comprises obtaining a power spectral density (PSD) from the metric, estimating a Doppler spectrum width using the PSD and classifying the at least one UE by comparing the Doppler spectrum width with one or more threshold values.

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 transmitting device includes: a transmission signal generation circuit that generates a transmission signal using a frame format including a legacy short training field (STF), a legacy channel estimation field (CEF), a legacy header field, an enhanced directional multi-gigabit (EDMG) header field, an EDMG-STF, an EDMG-CEF, and a data field; and a transmission circuit that transmits the generated transmission signal using one or more channels, wherein the legacy header field includes a data length field expressed by multiple bits, and the data length field indicates, to a legacy terminal, information related to a data length using all of the multiple bits, and indicates, to an EDMG terminal, information related to a data length using a subset of the multiple bits, and uses the remaining bit or bits to indicate information related to the one or more channels in which the transmission signal is transmitted.

This disclosure describes systems, methods, and devices related to a trigger-based null data packet (NDP) for channel sounding system. A device may send a trigger frame to a group of station devices, the group of station devices including a first station device, the trigger frame indicating a high efficiency (HE) long training field (HE-LTF) mode and a guard interval duration. The device may identify a HE trigger-based (TB) null data packet (NDP) received from the first station device, the HE TB NDP including a first packet extension field, wherein the HE TB NDP is associated with the HE-LTF mode and the guard interval duration indicated in the trigger frame. The device may send a downlink NDP including a second packet extension field, a second HE-LTF mode, and a second guard interval duration. The device may determine channel state information based on HE TB NDP received from the first station device.