Methods and apparatus adapted to address asymmetric conditions in a multi-antenna system. In one embodiment, the multi-antenna system comprises a wireless (e.g., 3G cellular) multiple-input, multiple-output (MIMO) system, and the methods and apparatus efficiently utilize transmitter and receiver resources based at least in part on a detected asymmetric condition. If an asymmetric condition is detected by the transmitter on any given data stream, the transmitter can decide to utilize only a subset of the available resources for that stream. Accordingly, the signal processing resources for that data stream are adapted to mirror the reduction in resources that are necessary for transmission. The transmitter signals the receiver that it will only be using a subset of the resources available, and the receiver adapts its operation according to the signaling data it receives. The multi-antenna system can therefore reduce power consumption as well as increasing spectral efficiency on the network.

Among other things, a communication system comprising at least one remote unit and controller is described. The at least one remote unit wirelessly exchanges radio frequency (RF) signals with mobile devices. Each RF signal comprises information destined for, or originating from, at least one of the mobile devices. The at least two remote units and the controller communicate baseband data corresponding to the information across an intermediate network. The at least two remote units each implement at least some physical layer processing for an air interface used to wirelessly communicate with the subscriber devices. The controller is configured to perform at least some receive signal processing using combined data resulting from combining at least some of the baseband data communicated from more than one of the at least two remote units.

Among other things, a communication system comprising at least one remote unit and controller is described. The at least one remote unit wirelessly exchanges radio frequency (RF) signals with mobile devices. Each RF signal comprises information destined for, or originating from, at least one of the mobile devices. The at least two remote units and the controller communicate baseband data corresponding to the information across an intermediate network. The at least two remote units each implement at least some physical layer processing for an air interface used to wirelessly communicate with the subscriber devices. The controller is configured to perform at least some receive signal processing using combined data resulting from combining at least some of the baseband data communicated from more than one of the at least two remote units.

A user equipment (UE) transmits over multiple antenna ports and receives a control message from a base station in a wireless communication network. The control message comprises a precoding matrix indication field configurable to a first, second, and third configuration. The first configuration identifies precoding matrices in both a first set of precoding matrices and a second set of precoding matrices. The second configuration identifies precoding matrices in the second set of precoding matrices but not in the first set of precoding matrices. The third configuration identifies precoding matrices in a third set of precoding matrices in addition to the first and second sets. The precoding matrices in the sets are precoding matrices for transmissions from the UE. Each set of precoding matrices corresponds to a respective coherence capability. For a maximum of four spatial layers, the first, second, and third configurations occupy 5, 4, and 6 information bits, respectively.

An electronic device includes a multiple input, multiple output (MIMO) antenna array comprising a plurality of antenna elements configured for MIMO communication across a network. One or more sensors detect a triggering event altering a radiation correlation pattern between at least two antenna elements of the plurality of antenna elements. One or more processors then select, in response to the one or more sensors detecting the triggering event, a quantity of antenna elements from the plurality of antenna elements available for engagement in the MIMO communication across the network as a function of the radiation correlation pattern.

A communication system includes remote units to exchange radio frequency (RF) signals with mobile devices, at least some of the RF signals comprising information destined for, or originating from, a mobile device. The communication system also includes a controller comprising one or more modems and connected to an external network, at least one of the modems being a baseband modem and being configured to pass first data corresponding to the information. The controller is separated from the remote units by an intermediate network over which second data corresponding to the information is carried in frames between the controller and the remote units. The second data comprises baseband data, and at least some of the baseband data is compressed in a frequency domain. The remote units and the controller are configured to compress the baseband data for transmission over the intermediate network.

A communication system includes remote units to exchange radio frequency (RF) signals with mobile devices, at least some of the RF signals comprising information destined for, or originating from, a mobile device. The communication system also includes a controller comprising one or more modems and connected to an external network, at least one of the modems being a baseband modem and being configured to pass first data corresponding to the information. The controller is separated from the remote units by an intermediate network over which second data corresponding to the information is carried in frames between the controller and the remote units. The second data comprises baseband data, and at least some of the baseband data is compressed in a frequency domain. The remote units and the controller are configured to compress the baseband data for transmission over the intermediate network.

An apparatus and method for transmitting reference signal and a communication system. The method includes: transmitting first information on one or more beams formed by a plurality of antennas in beam sweeping duration, the first information at least comprising a synchronization channel, a first reference signal and a physical broadcast channel. Hence, a receiving device may demodulate the physical broadcast channel by using the first reference signal, thereby achieving design of beam reference signals in a beam sweeping system.

An apparatus and method for transmitting reference signal and a communication system. The method includes: transmitting first information on one or more beams formed by a plurality of antennas in beam sweeping duration, the first information at least comprising a synchronization channel, a first reference signal and a physical broadcast channel. Hence, a receiving device may demodulate the physical broadcast channel by using the first reference signal, thereby achieving design of beam reference signals in a beam sweeping system.

Methods and apparatus are provided for transmission and reception of common channel information in a mobile communication system using multi-antenna-based beam-forming. A number of beams to be used for transmission to a terminal is determined at a base station. The common channel information is generated corresponding to the number of beams. The common channel information is transmitted from the base station to the terminal through one of the beams.