This disclosure provides systems, methods, and apparatuses, including computer programs encoded on computer storage media, for wireless communication. In one aspect of the disclosure, a method for wireless communication performed by a user equipment (UE) includes receiving first and second indications of respective first and second sets of subcarriers associated with respective first and second modulation orders. Each subcarrier of the second set of subcarriers is associated with a first RF spur associated with the network node. The method further includes demodulating respective first and second signals concurrently received on the respective first and second sets of subcarriers in accordance with the respective first and second modulation orders. Other aspects and features are also claimed and described.

A receiving circuit capable of estimating frequency offset includes a front circuit and a calculation circuit. The front circuit receives a remote signal to generate a received signal. The calculation circuit includes: an exponentiation module, calculating an exponent of a power to generate a high-order signal; a frequency-domain transform module, performing frequency-domain transform on the high-order signal to generate a spectrum; a peak searching module, searching for a peak of the amplitude of the spectrum to generate a peak coordinate value reflecting a frequency where the peak occurs; an offset estimating module, adding the peak coordinate value with a compensation value to generate a sum, dividing the sum by a first divisor to generate a remainder, subtracting the compensation value from the remainder to generate a difference, and dividing the difference by a second divisor to generate an offset estimation value reflecting the frequency offset.

Various embodiments provide for systems and methods for signal conversion of one modulated signal to another modulated signal using demodulation and then re-modulation. According to some embodiments, a signal receiving system may comprise an I/Q demodulator that demodulates a first modulated signal to an in-phase (I) signal and a quadrature (Q) signal, an I/Q signal adjustor that adaptively adjusts the Q signal to increase the signal-to-noise ratio (SNR) of a transitory signal that is based on a second modulated signal, and an I/Q modulator that modulates the I signal and the adjusted Q signal to the second modulated signal. To increase the SNR, the Q signal may be adjusted based on a calculated error determined for the transitory signal during demodulation by a demodulator downstream from the I/Q modulator.

A channel estimation technique suitable for implementation at a digital communication receiver such as an optical signal receiver apparatus includes receiving, over a communication channel, a transmission comprising a sequence of modulated symbols, estimating, at multiple frequencies, estimated values of a channel transfer function of the communication channel and selectively revising the estimated values of channel transfer function by reducing glitches in the estimated values of the channel transfer function.

A method includes receiving a signal at a receiver device via a channel from a transmitter device and determining a frequency domain representation of the signal. The signal includes multiple modulation symbols. The method further includes detecting a first symbol of the signal and determining a time domain representation of a distortion estimate associated with the first symbol using a distortion recovery receiver (DRR) technique. The method further includes subtracting the distortion estimate from the first symbol to generate an updated estimate of the first symbol. The method further includes determining a frequency domain representation of a second symbol using a value that is based on a frequency domain representation of the distortion estimate and that is further based on a frequency domain representation of a quantized version of the updated estimate of the first symbol.

An apparatus for estimating carrier frequency offset includes an M.sup.th-power circuit, a spectrum generating circuit, a spectrum adjusting circuit, a peak frequency determining circuit and a frequency offset determining circuit. The M.sup.th-power circuit performs an M.sup.th-power calculation on an input signal to generate an M.sup.th-power calculation result. The spectrum generating circuit generates a spectrum according to the M.sup.th-power calculation result. The spectrum adjusting circuit identifies a partial energy peak value in a partial frequency range from the spectrum, and increases the partial energy peak value to be higher than any other energy in the spectrum to generate an adjusted spectrum. The peak frequency determining circuit identifies a peak frequency having a maximum energy peak value from the adjusted spectrum. The frequency offset determining circuit determines an estimated carrier frequency offset result according to the peak frequency.

Aspects of the disclosure relate to a coexistence of a first radio access technology (RAT), such as a fifth generation (5G) new radio (NR) technology with a second RAT, such as a narrow-band internet-of-things (NB-IOT) technology. In a first aspect, a 5G NR resource block size and an NB-IOT resource block size are defined, and a compatible alignment of an NB-IOT resource block and a 5G NR resource block is identified. An offset associated with the compatible alignment is then determined in which the offset is within a threshold offset and facilitates an identification of a valid NB-IOT resource block. In a second aspect, an offset associated with a compatible alignment of a 5G NR resource block and an NB-IOT resource block is ascertained, and a channel raster is shifted according to the offset associated with the compatible alignment.

An apparatus and method for broadcast signal frame using a bootstrap including a symbol for signaling a BICM mode and OFDM parameters of a preamble, together are disclosed. An apparatus for generating broadcast signal frame according to an embodiment of the present invention includes a time interleaver configured to generate a time-interleaved signal by performing interleaving on a BICM output signal; and a frame builder configured to generate a broadcast signal frame including a bootstrap and a preamble using the time-interleaved signal. In this case, the bootstrap includes a symbol for signaling a BICM mode and OFDM parameters of L1-Basic of the preamble, together.

An apparatus for estimating carrier frequency offset includes an M.sup.th-power circuit, a spectrum generating circuit, a spectrum adjusting circuit, a peak frequency determining circuit and a frequency offset determining circuit. The M.sup.th-power circuit performs an M.sup.th-power calculation on an input signal to generate an M.sup.th-power calculation result. The spectrum generating circuit generates a spectrum according to the M.sup.th-power calculation result. The spectrum adjusting circuit identifies a partial energy peak value in a partial frequency range from the spectrum, and increases the partial energy peak value to be higher than any other energy in the spectrum to generate an adjusted spectrum. The peak frequency determining circuit identifies a peak frequency having a maximum energy peak value from the adjusted spectrum. The frequency offset determining circuit determines an estimated carrier frequency offset result according to the peak frequency.

A method for generating clock signals includes dividing an input clock signal to obtain a first in-phase output clock signal, dividing an inverted version of the input clock signal to obtain a first quadrature output clock signal, delaying edges in the input clock signal to obtain a second quadrature output clock signal, selecting a full-rate output to provide a multiphase output clock in a first mode of operation, and selecting a half-rate output to provide the multiphase output clock in a second mode of operation. The first quadrature output clock signal is a quadrature version of the first in-phase output clock signal. The first in-phase output clock signal and the first quadrature output clock signal are included in the full-rate output. The second quadrature output clock signal is included in the half-rate output and is a quadrature version of the input clock signal.