A securely pre-coded orthogonal frequency division multiplexing (SP-OFDM) system includes a transmitter configured to transmit a secure transmit signal through a dynamic constellation and a receiver configured to recover the original signal from the received secure transmit signal. It is aimed to reinforce the physical layer security of wireless communications under hostile interference. Potential applications include 4G and 5G communication systems, ASTC3.0 HDTV systems, WiFi systems, and any future wireless systems that utilize OFDM.

An transmission apparatus of the present disclosure comprises a transmission signal generator which, in operation, generates a transmission signal that includes a non-legacy preamble and a data field, the non-legacy preamble comprising a first field for indicating a number of spatial streams (Nss) in the data field and a second field for indicating one of a plurality of modulation and coding schemes (MCSs), wherein two or more frequency diversity transmission schemes are supported and each of the two or more frequency diversity transmission schemes is specified based on a value of the Nss; and a transmitter which, in operation, transmits the generated transmission signal.

A system that incorporates the subject disclosure may include, for example, a method for measuring a power level in at least a portion of a plurality of resource blocks occurring in a radio frequency spectrum, wherein the measuring occurs for a plurality of time cycles to generate a plurality of power level measurements, calculating a baseline power level according to at least a portion of the plurality of power levels, determining a threshold from the baseline power level, and monitoring at least a portion of the plurality of resource blocks for signal interference according to the threshold. Other embodiments are disclosed.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, obtaining performance parameters in a communications network, identifying a degradation in performance of one or more nodes of the communications network according the monitored performance parameters, and initiating corrective action to mitigate the degradation in performance of the one or more nodes of the communications network. Other embodiments are disclosed.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, identifying a selection of a SINR measurement target of a number of different SINR measurement targets. A SINR measurement of a second base station based on the SINR measurement target is obtained prior to a changing of an amplitude of a portion of a signal of a first base station. A determination is made as to whether the changing of the amplitude of the portion of the signal has reduced a second average SINR measurement of the second base station below a SINR threshold. In response to determining that the changing of the amplitude of the portion of the signal has reduced the second average SINR measurement of the second base station below the SINR threshold, the changing of the amplitude of the portion of the signal is reversed. Other embodiments are disclosed.

A system that incorporates the subject disclosure may perform, for example, a method that determines at least one threshold for detecting signal interference in a first plurality of segments occurring in a first radio frequency spectrum of a first wireless communication system, detecting a pattern of recurrence over time of signal interference in a segment of the first plurality of resource blocks according to the at least one threshold, and performing one or more mitigation steps to mitigate the signal interference without filtering the signal interference where the one or more mitigation steps include at least one of transmitting signals out of phase from the signal interference, adjusting transmit power, increasing power in a resource block of a long term evolution communication session, performing beam steering, or changing time parameters for the resource block without changing to a new resource block. Other embodiments are disclosed.

A method and an apparatus for transmitting/receiving a downlink signal in a wireless communication system are provided. Carrier information about a second carrier that is different from a first carrier can be transmitted on the first carrier. Downlink data for UE can be transmitted on the second carrier based on the carrier information. The first carrier is a carrier having a synchronisation signal and a physical broadcast channel, and the second carrier can be a carrier without any synchronisation signals or physical broadcast channels. The first carrier can be operated on a single resource block in a guard frequency that is used in the wireless communication system.

A system that incorporates the subject disclosure may include, for example, a process that includes adjusting a filter in electrical communication between an input terminal and a demodulator. The filter is applied to an information bearing signal, e.g., to mitigate interference, received at the input terminal, resulting in a filtered signal. An error signal is received, indicative of errors detected within information obtained by demodulation of a modulated carrier of the filtered signal. A modified filter state is determined in response to the error signal and the filter is adjusted according to the modified filter state, e.g., to improve mitigation of the interference. Other embodiments are disclosed.

A system that incorporates the subject disclosure may include, for example, a device comprising a memory to store instructions and a processor coupled to the memory, wherein responsive to executing the instructions, the processor performs operations. The operations comprise receiving signals over a spectrum of frequencies, providing location data of the device to a base station, receiving a request from a base station to perform a spectral analysis of the signals, detecting an interference among the signals, and providing, in response to the request, data to the base station regarding a source of the interference, wherein the data comprises a location of the source relative to the device, spectral data for identifying the source, and a time a frequency of occurrence of the interference. Other embodiments are disclosed.

There is provided mechanisms for beamformed reception of downlink reference signals. A. method is performed by a terminal device. The method comprises obtaining direction-wise measurements of interference experienced by the terminal device. The method comprises generating, based on the direction-wise measurements of interference, a beam having a beam gain that is lower in those directions where a first interference level is experienced than in those directions where a second interference level is experienced, where the first interference level is higher than the second interference level. The method comprises receiving, using the generated beam, downlink reference signals from a network node.