Embodiments disclose a method and an apparatus for transmitting indication information. The method includes: determining, according to one or more codebooks, a first codebook to be used by a terminal device to send an uplink data stream; determining codebook indication information used to indicate the first codebook; and determining codebook indication information used to indicate the first codebook. For the method and the apparatus for transmitting indication information according to embodiments of the present invention, a network device determines, according to one or more codebooks, a first codebook to be used by a terminal device to send an uplink data stream, determines codebook indication information used to indicate the first codebook, and sends the codebook indication information to the terminal device, so that the terminal device can determine the first codebook assigned by the network device and transmit data by using the first codebook.

According to an example aspect of the present invention, there is provided an apparatus for a base station including at least one processing core, configured to cause the apparatus at least to define a first cluster of time-division duplex user equipments at least partly by including in the first cluster user equipments whose uplink signals may be received using a single first directional beamforming beam, determine a ratio of received signal strengths of a pair of user equipments in the first cluster, the pair including a first user equipment associated with the apparatus and a second user equipment associated with a neighbouring base station device, and responsive to the ratio fulfilling a predetermined condition, inform the neighbouring base station device of a scheduling plan of the first user equipment.

In some embodiments, a method sets a threshold over a frequency spectrum and receives a set of measurements that measures interference between a set of network devices over the frequency spectrum. A set of metric values based on the set of measurements is compared to the threshold at a plurality of points over the frequency spectrum. The method then selects whether the set of network devices are in a group that interfere with communications of each other based on the comparing.

In an example, there is disclosed an apparatus, having: a first network interface, having a first clock and a local communication driver to communicatively couple the first network interface to a second network interface having a second clock; and one or more logic elements, including at least one hardware logic element, providing a synchronization engine to: send a first plurality of data words from the first wireless interface to the second wireless interface via the local communication driver; receive back from the second wireless interface a second plurality of data words; assign a plurality of error rates to the data words of the second plurality of data words, the plurality of error rates indicating match or mismatch; identify a range of least error values within the plurality of error rates; and select an agreed baud rate from within the range.

Embodiments of this application disclose a communication method and apparatus. The method includes: After determining that a first base station is affected by atmospheric duct interference from a second base station, the first base station sends first information to the second base station through a core network, to notify the first base station that the first base station causes atmospheric duct interference to the second base station. After determining that the first base station is affected by the atmospheric duct interference from the second base station, the first base station notifies the second base station in a wired link manner, and specifically, may send the first information to the second base station through the core network.

A radio communication apparatus that performs radio communication according to a multicarrier scheme includes: a transmitting unit including a null inserting unit that dispersedly arranges null symbols in a two-dimensional space of time and frequency in radio data, and a differential modulating unit that performs differential modulation on a data symbol part other than the null symbols; and a receiving unit including an interference measuring unit that measures interference power for a data symbol that is a measurement target by using a null symbol adjacent to the data symbol in the two-dimensional space of time and frequency, and a delay detecting unit that performs weighting on each data symbol according to the interference power measured for each data symbol and that performs delay detection between data symbols.

A first transmission signal z.sub.1(t) and a second transmission signal z.sub.2(t) are generated from a first modulated signal s.sub.1(t) and a second modulated signal s.sub.2(t) by using a precoding matrix, and parameters of the precoding matrix are calculated from feedback information.

A signal power tester in provided. The signal power tester includes at least one interface to communicatively couple the signal power tester unit to a front-haul communication link used for communicating front-haul data to a remote radio head (RRH) having one or more antenna ports. The signal power tester further comprises a programmable processor, coupled to the interface, configured to execute software, wherein the software is operable to cause the signal power tester to do the following: determine a representative segment indicative of a noise floor of a communication signal; determine whether the representative segment meets selected criterion; determine a translation factor for the representative segment; and measure power of the communication signal based on applying the translation factor.

Embodiments of the present disclosure relate to channel state information measurement in communication networks. According to embodiments of the present disclosure, the measurement resource unit, MRU, configuration is determined based on the number of MRU and the identity of the cell. The MRU configuration is scalable and the set of MRUs is reused by the network. In this way, the resources are saved and the accuracy is improved.

The present invention concerns a method for correcting a frequency shift on symbols received by a receiver, each symbol being composed of N samples and of a cyclic prefix of a predetermined number Δ samples, the Δ samples being a copy of Δ samples of the N samples. The receiver: —calculates for each symbol, a correlation between at most the Δ samples of the cyclic prefix and the at most Δ samples among the last samples, —averages the correlations over a number of symbols and determines one smooth frequency shift estimation for each averaged correlation, —calculates an exponential from the smooth frequency shift estimation, delays the received symbols by a delay, —multiplies the exponential by the delayed received symbols.