Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and relevant device. The generated preamble symbol contains: a time-domain symbol with a first three-segment structure; or a time-domain symbol with a second three-segment structure; or a free combination of several time-domain symbols with the first three-segment structure and/or several time-domain symbols with the second three-segment structure arranged in any order. Using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to perform coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels, and generating a postfix or hyper prefix based on the truncation of the entirety or a portion of the time-domain main body signal would enable the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and relevant device. The generated preamble symbol contains: a time-domain symbol with a first three-segment structure; or a time-domain symbol with a second three-segment structure; or a free combination of several time-domain symbols with the first three-segment structure and/or several time-domain symbols with the second three-segment structure arranged in any order. Using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to perform coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels, and generating a postfix or hyper prefix based on the truncation of the entirety or a portion of the time-domain main body signal would enable the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and relevant device. The generated preamble symbol contains: a time-domain symbol with a first three-segment structure; or a time-domain symbol with a second three-segment structure; or a free combination of several time-domain symbols with the first three-segment structure and/or several time-domain symbols with the second three-segment structure arranged in any order. Using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to perform coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels, and generating a postfix or hyper prefix based on the truncation of the entirety or a portion of the time-domain main body signal would enable the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and relevant device. The generated preamble symbol contains: a time-domain symbol with a first three-segment structure; or a time-domain symbol with a second three-segment structure; or a free combination of several time-domain symbols with the first three-segment structure and/or several time-domain symbols with the second three-segment structure arranged in any order. Using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to perform coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels, and generating a postfix or hyper prefix based on the truncation of the entirety or a portion of the time-domain main body signal would enable the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

A receiver (1) includes a frequency finite difference calculator (14) that sets, among a plurality of frequency components constituting a first frequency signal, a frequency component other than frequency components including notches detected by signal-strength finite difference calculators (13_1 and 13_2) as a reference frequency component and calculates a relative phase of a frequency component of a second frequency signal corresponding to the reference frequency component, and a combiner (19) that adjusts, according to a calculation result by a relative-phase calculator, a phase of the second frequency signal and, then, compensates the frequency component including the notch among the plurality of frequency components constituting the first frequency signal with the corresponding frequency component of the second frequency signal.

A method of providing wireless communications in a wireless network can include wirelessly receiving a chirp spread-spectrum modulated signal at a first gateway device, the chirp spread-spectrum modulated signal being transmitted by a remote client device. The chirp spread-spectrum modulated signal can be demodulated at the first gateway device to provide demodulated data at the first gateway device. The demodulated data can be processed to provide an indication that a decode of a packet including the demodulated data failed. Time adjacent chirps included in the demodulated data can be combined to provide combined data at the first gateway device. A message can be transmitted from the first gateway device to a remote server responsive to an amplitude of the combined data exceeding a threshold value and the indication that the decode of the packet including the demodulated data failed.

An apparatus, comprising: circuitry configured, in response to receipt of input data, to transmit a stream of symbols of a constellation to a modulator for modulation onto a carrier wherein a frequency of occurrence of symbols in the stream is dependent upon a probability-amplitude distribution for symbols of the constellation, wherein the probability-amplitude distribution has a kurtosis less than a target value and a shape of the probability-amplitude distribution causes low-amplitude symbols to occur more frequently on average in the stream than high-amplitude symbols.

A method of providing wireless communications in a wireless network can include wirelessly receiving a chirp spread-spectrum modulated signal at a first gateway device, the chirp spread-spectrum modulated signal being transmitted by a remote client device. The chirp spread-spectrum modulated signal can be demodulated at the first gateway device to provide demodulated data at the first gateway device. The demodulated data can be processed to provide an indication that a decode of a packet including the demodulated data failed. Time adjacent chirps included in the demodulated data can be combined to provide combined data at the first gateway device. A message can be transmitted from the first gateway device to a remote server responsive to an amplitude of the combined data exceeding a threshold value and the indication that the decode of the packet including the demodulated data failed.

A method is provided of receiving user data from multiple transmitters, the user data from each transmitter having been encoded as a Low Density Lattice codeword, and the multiple Low Density Lattice codewords having been transmitted so as to be received as a combined signal at a receiver, the method of receiving comprising the steps of: (i) receiving the signal, (ii) calculating coefficients of linear combinations of the codewords from the multiple transmitters, (iii) calculating a scaling factor to be applied to the signal based on the coefficients, (iv) applying the scaling factor to the signal to provide a linear combination of the codewords, (v) decoding the linear combination of the codewords based on channel state information to obtain an optimal independent linear combination of user data, (vi) repeating steps (ii), (iii) (iv) and (v) to obtain at least as many optimal independent linear combinations as the number of transmitters, and recovering the user data from the optimal independent linear combinations.

Disclosed is a device capable of compensating for amplitude-modulation to phase-modulation distortion. The device includes a transmitter and a controller. The transmitter includes an amplifier circuit, a phase-shift adjustment circuit, and an output circuit. The amplifier circuit is configured to output an amplified signal according to an input signal. The phase-shift adjustment circuit, set between the amplifier circuit and the output circuit, includes at least one of an adjustable capacitor and an adjustable inductor and is configured to adjust the phase shift of the amplified signal according to a control signal. The output circuit is configured to output an output signal according to the amplified signal. The controller is configured to generate the control signal according to the input signal, in which the control signal varies with the input signal.