A transmission apparatus maps a first stream of input data to first complex symbols in serial format and convert them into first complex symbols in parallel format. They are inverse Fourier transformed into OFDM signals associated with multiple subcarriers that are transmitted via a first antenna over the multiple subcarriers in a same frequency band over a same time period that includes a same set of time slots. First pilot information is transmitted via a first antenna on a first one of a plurality of pilot subcarriers during the same set of time slots, and second pilot information is sent via a first antenna on a second one of a plurality of pilot subcarriers during the same set of time slots. The second pilot information is different from the first pilot information. A second stream of input data is similarly transformed to form second OFDM signals transmit via a second antenna over the multiple subcarriers in the same frequency band over the same time period that includes the same set of time slots. The first pilot information is transmitted via the second antenna on the second pilot subcarrier during the set of same time slots, and the second pilot information is transmitted on one of the pilot subcarriers during the same set of time slots.

The present invention relates to a method in which a user equipment receives a downlink signal from a base station in a wireless communication system that supports downlink mimo transmission according to one embodiment of the present invention comprises: receiving downlink control information that includes information indicative of the number of layers (n, 1n8) where one or two enabled code words of the downlink mimo transmission are mapped; on the basis of the downlink control information, receiving downlink data transmitted over the respective n layers and a ue-specific reference signal for each of the n layers; and decoding the downlink data on the basis of the ue-specific reference signals, wherein the information indicative of the number of layers can further include information on a code for identifying the ue-specific reference signals.

A composite signal may be generated with code division multiplexing (CDM) and time division multiplexing (TDM) pilots. A first pilot sequence may be a CDM pilot sequence. A second pilot sequence may have TDM pilot sequences including a cyclic prefix. The composite signal may have a cyclic prefix time domain portion based on the cyclic prefix and a base portion of the composite signal.

A radio base station, user equipment (UE), and method of control signaling in wireless communication systems. Control information is transferred from a base station to at least one UE, via a plurality of common pilot channels. A set of unique pilot sequences is predefined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing specific control information. The UE, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information.

A device and method is which plurality of Zadoff-Chu sequences is allocated to a frame, a value of a parameter in the Zadoff-Chu sequence is different among the plurality of Zadoff-Chu sequences, and the Zadoff-Chu sequence allocated to the frame is different among a plurality of cells.

A data processing device includes a control channel model simple estimation apparatus performs control channel simple estimation, which does not include filter processing, a linear prediction apparatus performs linear prediction on a result obtained by the simple estimation, a pilot reconstruction apparatus reconstructs a first estimation result obtained by the linear prediction, a control channel data regeneration apparatus regenerates a pilot part in antenna data of a control channel of the user, and a control channel interference canceller removes the regenerated pilot part from antenna data of multiple users in order to obtain a control parameter part of the antenna data of the control channels of the multiple users.

Techniques for efficiently deriving uplink channel estimates without consuming much additional uplink resources are described. A user equipment (UE) may send a request for uplink resources on a request channel (REQCH) whenever the UE desires to transmit data on the uplink. The UE may send the REQCH on a set of subcarriers and from multiple antennas, e.g., send REQCH data on data subcarriers and pilot on pilot subcarriers. A Node B may receive the request, estimate the complex channel gains for the pilot subcarriers based on received pilot symbols, and coherently demodulate received data symbols based on the channel gain estimates. The Node B may estimate the complex channel gains for the data subcarriers based on demodulated data symbols and derive a channel estimate for each UE antenna based on the channel gain estimates for the pilot and data subcarriers. The Node B may use the channel estimates for MIMO scheduling, subband scheduling, and rate selection.

A network device for generating an expanded long training sequence with a minimal peak-to-average ratio. The network device includes a signal generating circuit for generating the expanded long training sequence. The network device also includes an Inverse Fourier Transform for processing the expanded long training sequence from the signal generating circuit and producing an optimal expanded long training sequence with a minimal peak-to-average ratio. The expanded long training sequence and the optimal expanded long training sequence are stored on more than 52 sub-carriers.

Obtaining a timing reference in wireless communication is facilitated when desiring to communicate with a weak serving base station (such as an evolved NodeB) in the presence of a stronger interfering base station. The user equipment (UE) may track a stronger interfering base station's timing, or the UE may track a timing that is derived by a composite power delay profile (PDP) from multiple base stations. The composite PDP may be constructed by adjusting individual base station PDPs according to a weighting scheme. The timing obtained in such a manner may be used for estimation of the channel of the interfering base station and cancelling interfering signals from the base station. It may also be used to estimate the channel of the serving base station after adding a backoff. The UE may track a stronger interfering base station's frequency, or the UE may track a composite frequency.

Network node and method in a network node, comprising: grouping a plurality of UEs into at least a first UE group and a second UE group; assigning a mutually orthogonal pilot sequence to each UE comprised in the first UE group; assigning a mutually orthogonal pilot sequence to each UE comprised in the second UE group; assigning a resource-offset to the UEs comprised in each UE group, by which each UE is allowed to start its transmission sub-frame in its Transmission Time Interval, TTI; and transmitting the assigned pilot sequences and the assigned resource-offset to UEs.