A base station transmits a message to a plurality of wireless devices in connected mode. The message comprises a subframe allocation bitmap indicating a plurality of subframes. The plurality of subframes comprises a plurality of almost blank subframes. During majority of symbols of an almost blank subframe of a base station, signals are transmitted at an almost blank subframe power level that is different from a transmit power during a non-almost blank subframe.

A method for signal transmission includes determining whether to perform repeated transmissions for a time length of a multiplication of L and M or more, wherein L indicates the overlapping factor of the system and M indicates a number of quadrature amplitude modulation (QAM) filter bank multi-carrier (FBMC) symbols, determining information on a type of the repeated transmissions to be performed, and transmitting FBMC symbols using a transmit power determined based on the type of the repeated transmissions. A base station includes a transceiver unit to send and receive signals, a control unit configured to determine whether to perform repeated transmissions for a time length of a multiplication of L and M or more, determine information on a type of the repeated transmissions to be performed, and transmit FBMC symbols using a transmit power determined based on the type of the repeated transmissions.

A method for signal transmission includes determining whether to perform repeated transmissions for a time length of a multiplication of L and M or more, wherein L indicates the overlapping factor of the system and M indicates a number of quadrature amplitude modulation (QAM) filter bank multi-carrier (FBMC) symbols, determining information on a type of the repeated transmissions to be performed, and transmitting FBMC symbols using a transmit power determined based on the type of the repeated transmissions. A base station includes a transceiver unit to send and receive signals, a control unit configured to determine whether to perform repeated transmissions for a time length of a multiplication of L and M or more, determine information on a type of the repeated transmissions to be performed, and transmit FBMC symbols using a transmit power determined based on the type of the repeated transmissions.

A first base station provides overlapping coverage area with second base stations and third base stations. Second base stations allow access to wireless devices and configure a second plurality of almost blank subframes. Second base stations configure the same set of subframes as the second plurality of almost blank subframes. Third base stations allow access to a restricted subset of wireless devices and configure a third plurality of almost blank subframes. At least two base stations in the third base stations configure different set of subframes as the second plurality of almost blank subframes.

A first base station provides overlapping coverage area with second base stations and third base stations. Second base stations allow access to wireless devices and configure a second plurality of almost blank subframes. Second base stations configure the same set of subframes as the second plurality of almost blank subframes. Third base stations allow access to a restricted subset of wireless devices and configure a third plurality of almost blank subframes. At least two base stations in the third base stations configure different set of subframes as the second plurality of almost blank subframes.

A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

A base station transmits a message to a plurality of wireless devices in connected mode. The message comprises a subframe allocation bitmap indicating a plurality of subframes. The plurality of subframes comprises a plurality of almost blank subframes. During majority of symbols of an almost blank subframe of a base station, signals are transmitted at an almost blank subframe power level that is different from a transmit power during a non-almost blank subframe.

A base station transmits a message to a plurality of wireless devices in connected mode. The message comprises a subframe allocation bitmap indicating a plurality of subframes. The plurality of subframes comprises a plurality of almost blank subframes. During majority of symbols of an almost blank subframe of a base station, signals are transmitted at an almost blank subframe power level that is different from a transmit power during a non-almost blank subframe.