A communication apparatus includes a receiver and a decoder. The receiver includes a plurality of antenna elements and, in operation, receives from a base station apparatus a modulated signal mapped to one of a plurality of subframes defined in a frame corresponding to a communicable range to which the communication apparatus belongs. The plurality of subframes are defined by time-division, frequency-division, or time-and-frequency division of the frame. A maximum number of modulated signals that can be simultaneously transmitted in a subframe from the base station apparatus varies depending on the communicable range. The decoder, in operation, decodes the received modulated signal.

Disclosed is a wireless communication base station apparatus whereby it is possible to prevent degradation of throughput of LTE terminals, even when LTE terminals and LTE+ terminals are present together. In this apparatus, a setting section (105) sets in each subframe a resource block in which is arranged a reference signal that is employed solely by LTE+ terminals, based on the pattern of arrangement of reference signals employed solely by LTE+ terminals. In the case of symbols that are mapped to antennas (110-1) to (110-4), an arrangement section (106) arranges the characteristic cell reference signals employed by both LTE terminals and LTE+ terminals in all of the resource blocks in a single frame. In contrast, in the case of the symbols that are mapped to the antennas (110-5) to (110-8), the arrangement section (106) arranges in some of the resource blocks, that are set in accordance with the setting results input from a setting section (105), the characteristic cell reference signals that are employed solely by the LTE+ terminals.

A wireless telecommunications system that mitigates infrasymbol interference due to Doppler-shift and multipath and enables multiple access in one radio channel. Embodiments of the present invention are particularly advantageous for wireless telecommunications systems that operate in high-mobility environments, including high-speed trains and airplanes.

A method and apparatus for generating and utilizing spreading sequence codebooks for a symbol-level sequence spreading is disclosed. In one embodiment, a method performed by a wireless communication device, comprising: receiving a first number from a wireless communication node; selecting a first spreading sequence codebook from at least one spreading sequence codebook; selecting a first spreading sequence from the first spreading sequence codebook according to the first number; and spreading data symbols according to the first spreading sequence, wherein the at least one spreading sequence codebook each comprises a plurality of spreading sequences configured based on one entry of a first sequence set after cyclic shifting operation, wherein the first sequence set before cyclic shifting operation is configured based on a second sequence set.

Disclosed is a wireless communication base station apparatus whereby it is possible to prevent degradation of throughput of LTE terminals, even when LTE terminals and LTE+ terminals are present together. In this apparatus, a setting section (105) sets in each subframe a resource block in which is arranged a reference signal that is employed solely by LTE+ terminals, based on the pattern of arrangement of reference signals employed solely by LTE+ terminals. In the case of symbols that are mapped to antennas (110-1) to (110-4), an arrangement section (106) arranges the characteristic cell reference signals employed by both LTE terminals and LTE+ terminals in all of the resource blocks in a single frame. In contrast, in the case of the symbols that are mapped to the antennas (110-5) to (110-8), the arrangement section (106) arranges in some of the resource blocks, that are set in accordance with the setting results input from a setting section (105), the characteristic cell reference signals that are employed solely by the LTE+ terminals.

The present disclosure relates to methods and devices for mitigating inter-cluster interference in clusters where one or more network nodes are transmitting in coordination using several transceiver antennas. In particular the disclosure relates to improved precoder algorithms to be used for coordinated multipoint transmission applications. The disclosure also relates to corresponding computer programs. The disclosure proposes a method, performed in a communication system, of mitigating inter-cluster interference, wherein the communication system is configured to coordinate transmissions of one or more wireless devices within two or more wireless device categories and one or more network nodes, wherein the one or more network nodes are transmitting in coordination to the wireless devices in the cluster using several transceiver antennas.

A method, base station (BS), user equipment (UE), apparatus, and computer program product for wireless communication are provided. An aggressor BS may cause a remote interference condition for a victim BS, and the victim BS may transmit a reference signal to the aggressor BS to enable a remote interference management (RIM) operation to be performed. However, the aggressor BS may be unable to identify the victim BS based at least in part on the reference signal, and may fail to transmit a reference signal as a response. Further, when the aggressor BS does transmit a reference signal, the victim BS may be unable to identify the aggressor BS. This may reduce an effectiveness of RIM operations. In some aspects, BSs may transmit reciprocal reference signals including identification information to enable effective RIM operations.

This application discloses example signal sending methods and apparatuses, and example signal processing methods and apparatuses. One example method includes generating, by a terminal device, a channel sounding reference signal (SRS). The terminal device can then send the SRS to a target base station, where the target base station detects, by using the SRS, that a change range of an uplink timing location of the terminal device is not less than a length of one SRS symbol.

A communication apparatus includes a receiver and a decoder. The receiver includes a plurality of antenna elements and, in operation, receives from a base station apparatus a modulated signal mapped to one of a plurality of subframes defined in a frame corresponding to a communicable range to which the communication apparatus belongs. The plurality of subframes are defined by time-division, frequency-division, or time-and-frequency division of the frame. A maximum number of modulated signals that can be simultaneously transmitted in a subframe from the base station apparatus varies depending on the communicable range. The decoder, in operation, decodes the received modulated signal.

A transmitting apparatus includes a first signal generating unit that generates, on the basis of data a first signal transmitted by single carrier block transmission; a second signal generating unit that generates, on the basis of an RS, a second signal transmitted by orthogonal frequency division multiplex transmission; a switching operator that selects and outputs the second signal in a first transmission period and selects and outputs the first signal in a second transmission period; an antenna that transmits the signal output from the switching operator; and a control-signal generating unit that controls the second signal generating unit such that, in the first transmission period, the RS is arranged in a frequency band allocated for transmission of the RS from the transmitting apparatus among frequency bands usable in OFDM.