According to an aspect of the present invention, a signal processor comprises an N-point phase FFT transformer operative to perform a FFT like transformation according to a first relation $Y\left[k\right]=\underset{n=0}{\overset{n=N-1}{.Math.}}{\exp }^{\left[j\mathrm{angle}\left[x\left(n\right)\right]\right]}*\exp \left[\frac{-j2\mathrm{kn}}{N}\right],$
wherein angle [x(n)] representing the phase of the signal x(n). In that, a plurality of butterfly units with each butterfly unit in the plurality of butterfly units comprises an add

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine, based at least in part on a decomposition rule for a discrete Fourier transform (DFT) block, a plurality of decomposition groups for tones, corresponding to a plurality of antenna ports of the UE, of a transmission. The UE may map the tones to the plurality of decomposition groups for transmission processing, and transmit, using the plurality of antenna ports, the transmission based at least in part on transmission processing. Numerous other aspects are provided.

A method performed in a radio access node includes the radio access node receiving a data for transmission to a second radio access node over a communication channel having an unlicensed spectrum. The method further includes, in response to receiving the data, the radio access node receiving a channel measurement signal over the communication channel. The method further includes the radio access node performing an N-point Fast Fourier Transform (FFT) on the channel measurement signal to produce a frequency domain signal with N bins. The method further includes the radio access node performing a power measurement on the frequency domain signal. The method further includes the radio access node analyzing the power measurement of the frequency domain signal. The method further includes the radio access node transmitting the data based on the analysis of the power measurement.

A calculation circuit for calculating a transform of an input sequence may include a plurality of butterfly computation circuits configured to perform a plurality of butterfly computations and to produce a plurality of outputs during each of a plurality of computation stages, a wired routing network configured to route a first plurality of outputs of the plurality of butterfly computation circuits from a first computation stage of the plurality of computation stages as input to the plurality of butterfly computation circuits during a second computation stage of the plurality of computation stages according to a reconfigurable routing configuration, and routing control circuitry configured to modify the reconfigurable routing configuration for a third computation stage of the plurality of computation stages.

The present invention improves reception characteristics of a receiving apparatus based on OFDM. The receiving apparatus includes: a window timing selection unit that determines Fourier transform window start and end timings for a received signal(s) based on OFDM, based on a signal-to-interference power ratio and signal power in a Fourier transform window; and a Fourier transform unit that performs Fourier transform on the received signal(s) in accordance with the Fourier transform window start and end timings outputted by the window timing selection unit.

Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.

Disclosed herein is a broadcast signal receiver. The broadcast signal receiver according to an embodiment of the present invention includes a synchronization and demodulation module configured to perform detection and OFDM demodulation on a received broadcast signal, a frame parsing and deinterleaving module configured to parse and deinterleave the signal frame of the broadcast signal, a demapping and decoding module configured to convert the data of at least one Physical Layer Pipe (PLP) of the broadcast signal into a bit domain and to FEC-decode the PLP data, and an output processing module configured to receive the data of the at least one PLP and to output the received data in a data stream form.

Disclosed is a method pilot-aided channel estimation in Orthogonal Frequency Division Multiplexing (OFDM) systems regardless of the frequency selectivity severity of the channel is proposed.

Frame formatting for communications within single user, multiple user, multiple access, and/or MIMO wireless communications. A signal is processed within a communication device using at least two respective downclocking ratios (e.g., a first downclocking ratio applied to a first portion of the signal such as a frame or packet extracted there from, a second downclocking ratio applied to a second portion of the signal). Alternatively, a signal is divided into more than two respective portions, and different respective downclocking ratios are applied to those different respective portions (e.g., a first downclocking ratio applied to a first portion of the signal, and so on up to an n-th downclocking ratio applied to an n-th portion of the signal). Some implementations apply a singular or common downclocking ratio to more than one portion of the signal (which may be contiguous/adjacent or non-contiguous/non-adjacent within the signal).

An orthogonal frequency division multiplexing (OFDM) transmission system is provided which includes a data processing unit which generates a transmission signal using a plurality of tones including a reserved tone, a storage unit which stores Peak Reduction Kernel information according to the type of data symbol, and a compensation unit which retrieves the Peak Reduction Kernel information according to the type of data symbol from the storage unit and causes the retrieved information to be carried by the reserved tone included in the transmission signal. Therefore, a Peak-to-Average Power Ratio (PAPR) can be efficiently compensated.