A method and apparatus for performing an initial access procedure in a wireless communication system is provided. A low cost user equipment (UE) transmits a list of capabilities to a network, and receives a reject message from the network when at least one of the capabilities is not supported by the network. The list of capabilities may be transmitted during a random access procedure via a random access preamble on a physical random access channel (PRACH) or a message 3 on a physical uplink shared channel (PUSCH). The reject message may be received during the random access procedure a random access response or an acknowledge message for the message 3.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, receiving, via an antenna, a signal generated by a communication device, detecting passive intermodulation interference in the signal, the interference generated by one or more transmitters unassociated with the communication device, and the interference determined from signal characteristics associated with a signaling protocol used by the one or more transmitters. Other embodiments are disclosed.

A method for spread spectrum communication, a user equipment and a base station are provided in embodiments of the present disclosure. The method for spread spectrum communication applied to a user equipment includes: selecting spreading sequences for a plurality of symbols of data to be transmitted in a set of spreading sequences, respectively, wherein spreading sequences selected for at least two symbols are different; spreading the data by using the selected spreading sequences; transmitting the spread data.

In a case that a large number of terminal apparatuses accommodated in a contention based radio communication technology share a frequency resource, the number of data signals of the terminal apparatuses which are non-orthogonally multiplexed in the spatial domain increases. Therefore, in a case that the number of non-orthogonally multiplexed data signals of the terminals is considerably large, residual interference after removing interference in the reception processing degrades transmission performance. A transmission device for transmitting a data signal to a reception device includes a transmission processing unit configured to transmit the data signal without receiving SR transmission and control information for transmission authorization transmitted by the reception device, an identification signal multiplexing unit configured to multiplex an identification signal on an orthogonal resource, and a control information receiving unit configured to receive in advance a transmission parameter associated with the data signal transmission. The transmission parameter includes any of a first data transmission to transmit the data signal by using a continuous frequency resource and a second data transmission to transmit the data by using a discontinuous and equal interval frequency resource.

A method, wireless device (100) and network node (200) for performing sounding reference signal, SRS, transmission According to one aspect a method includes receiving a definition of one or more SRS resource sets to be configured, comprising at least one SRS transmission setting. The method further includes receiving an indication of a selected SRS resource set to use for a SRS transmission, from the one or more configured SRS resource sets and determining a precoding configuration for the SRS transmission based on the selected SRS resource set and the at least one SRS transmission setting. The method also includes transmitting a SRS according to the determined precoding configuration.

A method and apparatus for performing an initial access procedure in a wireless communication system is provided. A low cost user equipment (UE) transmits a list of capabilities to a network, and receives a reject message from the network when at least one of the capabilities is not supported by the network. The list of capabilities may be transmitted during a random access procedure via a random access preamble on a physical random access channel (PRACH) or a message 3 on a physical uplink shared channel (PUSCH). The reject message may be received during the random access procedure a random access response or an acknowledge message for the message 3.

An example method may include receiving, from a wireless sniffer, sniffer data for a window of time, where the sniffer data may include wireless signal data. The method may also include obtaining corresponding access point data from an access point in a wireless network for at least part of the window of time for which the sniffer data is received. The method may additionally include analyzing the sniffer data and the corresponding access point data to assess performance of the wireless network.

Systems, base stations, terminals, and methods for group-selective channel feedback in a wireless communication system are described. In one signal measurement method for a base station supporting Multiuser Multiple-Input Multiple-Output (MU-MIMO), the base station allocates a group identifier to a terminal group for performing and reporting signal measurements simultaneously. When the base station transmits control information including the group identifier, each one of terminals belonging to the terminal group performs signal measurement, generates signal measurement feedback, and simultaneously transmits the signal measurement feedback to the base station.

A receiver configured to receive first information on a configuration of a demodulation reference signal via higher layer signaling and receive downlink control information including second information on transmission of the demodulation reference signal via a physical downlink control channel, and a transmitter configured to transmit the demodulation reference signal and uplink data are included. The transmitter transmits the demodulation reference signal and the uplink data by using a same OFDM symbol based on at least the first information and the second information.

A wireless communication system includes a transmitter that discretely inserts null subcarriers into an OFDM-demodulated signal in time and frequency domains, and a receiver that receive signals by a first and second antennas. The receiver calculates a complex coefficient wherein a result of multiplying a first reception vector for each of the null subcarriers received by the first antenna by the complex coefficient is equal to an amplitude of a second reception vector of the corresponding null subcarrier received by the second antenna and is opposite in phase thereto, calculates a fourth reception vector by multiplying a third reception vector of any data subcarrier received by the first antenna by a coefficient that is obtained by interpolating the complex coefficient, and adds the fourth reception vector to a fifth reception vector of the any data subcarrier received by the second antenna.