A transmitting apparatus is provided. The transmitting apparatus includes: an L1 signaling generator configured to generate L1 signaling including first information and second information; a frame generator configured to generate a frame including a payload including a plurality of sub frames; and a signal processor configured to insert a preamble including the L1 signaling in the frame and transmit the frame. The first information includes information required for decoding a first sub frame among the plurality of sub frames. Therefore, a processing delay in a receiving apparatus is reduced.

Distortion caused by spurious components in a determined channel impulse response (CIR) is reduced. In an OFDM (orthogonal frequency-division multiplexing) system pilot signals are applied to different subcarriers of different symbols in accordance with a pilot transmission scheme. Channel estimates are determined by time-interpolation for some of the data slots of the received signal which do not already include a pilot signal. For each of a sequence of symbols, a respective Inverse Fast Fourier Transform is performed on the pilot signals and interpolated channel estimates in the data slots of that symbol, thereby determining a sequence of estimated CIRs for the sequence of symbols. Spurious channel components will vary across the sequence of estimated CIRs, whereas the true channel peaks will tend not to significantly vary across the sequence of estimated CIRs. Therefore the sequence of estimated CIRs can be filtered (e.g. with a low-pass filter) to attenuate the spurious components, thereby determining a CIR for the signal for which the distortion caused by the spurious components is reduced.

Methods and OFDM receivers for decoding an OFDM signal include estimating a channel impulse response from a pilot-dense symbol of the OFDM signal for each of a plurality of potential FFT window positions; determining a noise floor of each of the channel impulse responses; selecting the potential window position corresponding to the channel impulse response with the lowest noise floor as an optimum FFT window position; and decoding symbols of the OFDM signal using the optimum FFT window position.

A broadcast signal receiver includes a tuner for tuning a broadcast signal, a reference signal detector for detecting pilots from the tuned broadcast signal, a de-framer for de-framing a signal frame of the broadcast signal and deriving service data based on a number of carriers of the signal frame, and a decoder for performing error correction process on the derived service data.

Certain aspects of the present disclosure relate to techniques for estimating a channel using soft-windowing. A user equipment (UE) may determine, based on a cyclic prefix (CP) length of a channel, a timing window for sampling reference signals transmitted on the channel, determine a set of weights to apply to samples obtained within the determined timing window, wherein each weight corresponds to a sample obtained within the determined window, and estimate the channel by applying the weights to the samples.

A receiver comprises a radio frequency demodulation circuit configured to detect and to recover a received signal. The received signal includes in one or more frames a preamble comprising a plurality of bootstrap OFDM symbols. A first of the bootstrap OFDM symbols has a first time domain structure configured so that a receiver can synchronise to a useful part of the bootstrap OFDM symbols and one or more of the other bootstrap OFDM symbols have at least a second time domain structure and carry layer one signalling data indicating parameters for detecting and recovering payload data carried by the one or more frames. The receiver comprises a detector circuit configured to detect from one or more of the bootstrap OFDM symbols a synchronisation timing and an inverse Fourier transformer configured to convert the temporal length of the bootstrap OFDM symbols or the payload OFDM symbols from the time domain into the frequency domain in accordance with the identified synchronisation timing. The detection circuit includes a first correlator adapted to the first time domain structure of the first bootstrap OFDM symbol and one or more second correlators adapted to the second time domain structure of the one or more other bootstrap OFDM symbols, one or more delay units configured to delay a first correlation result produced by the first correlator and the at least one second correlation result produced by the one or more second correlators so that the correlation results are produced contemporaneously for the first and the one or more other bootstrap OFDM symbols

A method to generate a wireless waveform for use in a wireless communication system, a wireless communication system and computer program product thereof The method comprises the generation of a waveform for application in the wireless communication system characterized by significant phase noise, Doppler spread, multipath, frequency instability, and/or low power efficiency by at the transmitter side: creating a discrete-time instantaneous frequency signal {tilde over (f)}[n]; appending a cyclic prefix with length L.sub.CP to the beginning of the discrete-time instantaneous frequency signal {tilde over (f)}[n]; constructing a discrete-time unwrapped instantaneous phase [n]; constructing a discrete-time complex baseband signal, and appending at the beginning a Constant Amplitude Zero Autocorrelation, CAZAC, signal of length L.sub.CP for multipath detection; and passing the constructed discrete-time complex baseband signal through a digital-to-analog, DAC, converter to yield the continuous-time radio frequency signal s(t) after conversion to the carrier frequency.

Methods and OFDM receivers for decoding an OFDM signal include estimating a channel impulse response from a pilot-dense symbol of the OFDM signal for each of a plurality of potential FFT window positions; determining a noise floor of each of the channel impulse responses; selecting the potential window position corresponding to the channel impulse response with the lowest noise floor as an optimum FFT window position; and decoding symbols of the OFDM signal using the optimum FFT window position.

A transmitting apparatus is provided. The transmitting apparatus includes: an L1 signaling generator configured to generate L1 signaling including first information and second information; a frame generator configured to generate a frame including a payload including a plurality of sub frames; and a signal processor configured to insert a preamble including the L1 signaling in the frame and transmit the frame. The first information includes information required for decoding a first sub frame among the plurality of sub frames. Therefore, a processing delay in a receiving apparatus is reduced.

An O-RU may receive a PRACH preamble and a PUSCH within a plurality of symbols of a slot, the PRACH and the PUSCH having different numerology. The O-RU may filter a PUSCH CP for each symbol of the PRACH preamble through a FFT window per symbol of the PRACH preamble, the FFT window extending from the end of the PUSCH CP within a symbol to the end of the symbol, and perform FFT per the FFT window of each symbol of the PRACH preamble. The O-RU may extract I/Q data in frequency domain corresponding to the PRACH preamble, adjust phase shift of the extracted I/Q data to generate the I/Q data of the PRACH preamble accounting for shift of the each FFT window in time domain compared to FFT windows of PRACH CP filtered PRACH preamble and send the I/Q data of the PRACH preamble to an O-DU.