Different filtered-orthogonal frequency division multiplexing (f-OFDM) frame formats may be used to achieve the spectrum flexibility. F-OFDM waveforms are generated by applying a pulse shaping digital filter to an orthogonal frequency division multiplexed (OFDM) signal. Different frame formats may be used to carry different traffic types as well as to adapt to characteristics of the channel, transmitter, receiver, or serving cell. The different frame formats may utilize different sub-carrier (SC) spacings and/or cyclic prefix (CP) lengths. In some embodiments, the different frame formats also utilize different symbol durations and/or transmission time interval (TTI) lengths.

Embodiments of the present disclosure relate to systems and methods to generate a signal in a communication network. The method comprises filtering a discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) data signal, and one of a DFT-S-OFDM and orthogonal frequency division multiplexing (OFDM) reference signal (RS) using a data filter and a RS filter respectively, to produce filtered data signal and filtered RS. The RS filter has one to one relationship with the data filter. Thereafter, port mapping the filtered RS to a corresponding port assigned to the transmitter to obtain port mapped filtered RS, wherein the port mapped filtered RS comprises a first subset of non-zero locations comprising of the filtered RS values and a second subset of zero locations comprising of zero values.

Techniques are disclosed for allocating time-frequency resources in a system that uses multiple multicarrier modulation numerologies. According to one aspect, a method in a first wireless node comprises allocating (1310) time-frequency resources for use by a second wireless node, where said allocating comprises selecting, for use in multicarrier modulation in the allocated time-frequency resources, one of two or more subcarrier bandwidths that the second wireless node is adapted to use for modulating or demodulating of data. In some embodiments, the method further comprises sending (1320) resource allocation information to the second wireless node, the resource allocation information identifying the allocated time-frequency resources.

Disclosed are apparatuses for a communication device. An apparatus for a communication device includes control circuitry configured to use circular convolution for pulse shape filtering of a block of data symbols of a single carrier waveform to generate a block-wise single carrier (BWSC) symbol. The apparatus is also configured to insert one of a data-based cyclic prefix or a data-based cyclic postfix into the BWSC symbol one of before the pulse shape filtering or after the pulse shape filtering. An apparatus for a communication device includes control circuitry configured to remove one or more of a cyclic prefix or a cyclic postfix from a received BWSC symbol, and use circular convolution to demodulate the received BWSC symbol.

Disclosed are method and apparatus for enabling multiple access in a wireless communication system that can enable ultralow latency, ultra-reliable, and high throughput services. The disclosed multiple access method includes: allocating resources for a plurality of user terminals according to space and frequency; performing a discrete Fourier transform on a transmission symbol for each unit of the space, the transmission symbol composed of a plurality of sub-symbols and configured to be transmitted according to the allocated space and frequency resources; and applying a frequency filter and a spatial filter on the Fourier transformation result, and wherein the applying of the frequency filter and the spatial filter comprises: selecting a pulse shaping filter according to an arranged position of the allocated frequency resource for each unit of the space and applying the selected pulse shaping filter on a sample representing a result of applying a Fourier transform on the sub-symbol to a frequency domain.

Different filtered-orthogonal frequency division multiplexing (f-OFDM) frame formats may be used to achieve the spectrum flexibility. F-OFDM waveforms are generated by applying a pulse shaping digital filter to an orthogonal frequency division multiplexed (OFDM) signal. Different frame formats may be used to carry different traffic types as well as to adapt to characteristics of the channel, transmitter, receiver, or serving cell. The different frame formats may utilize different sub-carrier (SC) spacings and/or cyclic prefix (CP) lengths. In some embodiments, the different frame formats also utilize different symbol durations and/or transmission time interval (TTI) lengths.

Cyclic prefix based OFDM (CP-OFDM) signals can be filtered using a digital filter whose filter length exceeds the length of a cyclic prefix in CP-OFDM symbols of the signal. In one example, the duration of the filtered CP-OFDM symbol may be expressed by the following equation: M=N+L1, where M is the duration of the filtered CP-OFDM signal, N is a duration of the CP-OFDM signal, and L is the filter length of the digital filter. Digitally filtering the CP-OFDM signal may include convolving a filtering signal with the CP-OFDM signal. The digital filter may include a finite impulse response (FIR) filter or an infinite impulse response (IIR) filter. In some embodiments, a different digital filter may be applied to each sub-band of the CP-OFDM signal.

Disclosed are a roll-off period detection method, a symbol starting point detection method, a fractional frequency offset estimating method, and an OFDM downstream system using the same. A method of detecting a roll-off period in an OFDM downstream system according to an embodiment of the present disclosure may include: generating a temporary roll-off period by applying a windowing function to a signal having a preset length; and detecting a roll-off period based on any one of a cross correlation and a sum of differences between a detection target signal included in a range of two OFDM symbol signals based on a detection starting point, and the temporary roll-off period.

Various aspects described herein relate to techniques for timing control with filtering in orthogonal frequency division multiplexing (OFDM)-based wireless communications systems. In an aspect, the method includes determining whether time-domain filtering or frequency-domain filtering is used for a transmission signal waveform, and identifying a time delay based on a determination that the time-domain filtering is used for the transmission signal waveform. The method further includes applying a timing correction based on the identified time delay. The techniques described herein may apply to different communications technologies, including 5th Generation (5G) New Radio (NR) communications technology.

Method disclosed is applied to an OFDM wireless transmission system which includes at least two OFDM symbols, and includes: adding a zero power padding ZP to a tail end of each of the at least two OFDM symbols; adding data of N.sub.w consecutive points at one end of a first OFDM symbol of the at least two OFDM symbols to the ZP at the other end of the first OFDM symbol, so that the data of the N.sub.w points is a prefix and/or a suffix of the first OFDM symbol, where the first OFDM symbol includes data of N points, N>N.sub.w; and performing point multiplication processing with symmetric time domain window function on the data of the N.sub.w points at the two ends of the first OFDM symbol to which the prefix and/or the suffix is added, so that a sum of point coefficients corresponding to the symmetric time domain window function is 1.