In order to provide a wireless communication system capable of improving the throughput of wireless communication by effectively using frequency resources, in a wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other, the first wireless access point includes a transmission opportunity acquiring unit which acquires a transmission opportunity when data to be transmitted is generated; and a transmitting unit of permission for use which transmits permission for use of channels which are not scheduled to use within the first cell, to the second wireless access point in a period in which the transmission opportunity is acquired, and the second wireless access point includes a communication unit which communicates with the wireless station within the second cell via the channel in which the permission for use is acquired from the first wireless access point.

A method for performing self-interference cancellation by a communication device which uses an FDR mode can comprise the steps of: measuring the strength of a residual self-interference signal, after antenna and analog self-interference cancellation, for each subband with respect to a predetermined number of subbands configured in a communication device; determining the order of a nonlinear self-interference signal component, to be considered for channel estimation of a nonlinear self-interference signal, for each subband on the basis of the strength of the residual self-interference signal that has been measured for each subband; and performing channel estimation of the nonlinear self-interference signal on the basis of the order that has been determined for each subband.

A method and apparatus determine parameters and conditions for line of sight MIMO communication. Reference signals can be received at a receiving device from a transmitting device. A channel matrix can be measured based on the reference signals. At least two of a first line of sight channel parameter, a second line of sight channel parameter, and a third line of sight channel parameter can be extracted based on the channel matrix. The first line of sight channel parameter can be based on transmitting device antenna element spacing. The second line of sight channel parameter can be based on a product of the transmitting device antenna element spacing and a receiving device antenna element spacing. The third line of sight channel parameter can be based on the receiving device antenna element spacing. The at least two line of sight channel parameters can be transmitted to the transmitting device.

An echo detection circuit for a multi-carrier system includes a memory, a threshold generating circuit and an echo determining circuit. The memory stores a plurality of channel impulse response values of the multi-channel system. The channel impulse response values include a target channel impulse response value, a plurality of preceding channel impulse response values and a plurality of subsequent channel impulse response values; a threshold generating circuit, coupled to the memory, generating a threshold corresponding to the target channel impulse response according to the preceding channel impulse response values and the subsequent channel impulse response values; and an echo determining circuit, coupled to the threshold generating circuit and the memory, comparing the target channel impulse response value with the threshold to determine whether the target channel impulse response value corresponds to an echo path of the multi-carrier system.

There is provided a wireless communication system which can improve throughputs in wireless communication by effectively using frequency resources. In the wireless communication system including a plurality of wireless communication stations which may operate as wireless communication terminals or wireless base stations, the wireless communication station includes an access right acquisition means of acquiring an access right upon generating transmitting data; a determination means of determining whether or not different data destined to a plurality of wireless communication stations can be transmitted on different channels according to OFDMA; and a data transmitting means of transmitting data to the receivable wireless communication stations using OFDMA when the determination means determines that different data destined to a plurality of wireless communication stations can be transmitted on different channels.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, receiving, via an antenna, a signal generated by a communication device, detecting passive intermodulation interference in the signal, the interference generated by one or more transmitters unassociated with the communication device, and the interference determined from signal characteristics associated with a signaling protocol used by the one or more transmitters. Other embodiments are disclosed.

A noise power estimator, comprising: a first subtractor configured to generate at least one first signal by subtracting a reconstructed interference signal from a symbol of a received first time-domain training sequence; a second subtractor configured to generate at least one second signal by subtracting an estimated value for the first time-domain training sequence from one of the at least one first signal; an averaging circuit configured to generate at least one square average value by average the at least part of the at least one second signals; and a detector configured to detect a minimum value among the at least one square average value and output the minimum value as a noise power estimation value.

A telecommunication receiver is arranged for receiving related data originating from multiple antennas, which data have different times of arrival due to, for example, different delays. The receiver comprises an input buffer for buffering data, a transform unit for Fourier transforming the data received from the input buffer into transformed data, and an output buffer for buffering the transformed data received from the transform unit. The input buffer is arranged for passing each set of data items to the transform unit when the relevant data item has been received in the input buffer, while the transform unit is arranged for removing redundant parts of the data. In addition, the output buffer is arranged for synchronizing the transformed data. Thus the buffering for delay compensation is carried out in the output buffer.

A method of performing uplink channel estimation and a base station using the same are provided. The method is applicable to serve at least two UE equipments (UEs) in a communication system. The at least two UEs are located in at least two beam sectors respectively. The base station comprises a plurality of antennas. The method includes: determining whether multipath of the at least two UEs passing through a same beam sector; assigning a first and a second training sequence for a first UE and a second UE of the at least two UEs respectively; receiving a reference signal, wherein the reference signal is transmitted by the first UE and the second UE according to the first and the second training sequence; and performing channel estimation for the first UE and the second UE according to the reference signal, the first and the second training sequence.

A noise power estimator, comprising: a first subtractor configured to generate at least one first signal by subtracting a reconstructed interference signal from a symbol of a received first time-domain training sequence; a second subtractor configured to generate at least one second signal by subtracting an estimated value for the first time-domain training sequence from one of the at least one first signal; an averaging circuit configured to generate at least one square average value by average the at least part of the at least one second signals; and a detector configured to detect a minimum value among the at least one square average value and output the minimum value as a noise power estimation value.