A transmitter/receiver (1) up-converts, using an LO signal as a local oscillation signal, an IF signal having a predetermined frequency band, thereby generating a transmission signal RF.sub.TX. Moreover, the transmitter/receiver (1) generates a (LO+IF).sup.2 signal and a (LO−IF).sup.2 signal based on the IF signal and the LO signal. Using the LO signal obtained by adding-up of the (LO+IF).sup.2 signal and the (LO−IF).sup.2 signal, a reception signal RF.sub.RX is down-converted. Thus, a local oscillation signal generation unit of a receiving unit is not necessary.

An apparatus (7) for down-converting a sampled signal comprises a processing system (206) configured to apply a mixing-and-combining operation repeatedly to successive sub-sequences of N input samples, X, representative of a signal and having an initial sampling rate, M, to generate a sequence of output samples, Y, having an output rate, T, lower than the initial sampling rate M. The sub-sequences of the N input samples, X, are spaced at intervals that correspond to the output rate M. The mixing-and-combining operation generates a respective output sample Y from each sub-sequence, where Y depends on a set of products of the input samples X of the sub-sequence with respective values derived from a periodic mixing signal having a mixing frequency.

A direct digital synthesis transmitter that uses a programmable digital circuit to generate a digital signal representing at least one radio frequency signal, the generated signal is filtered, amplified by an amplifier, and provided to a transmission antenna without upconversion. The transmitter generating the digital signal at a desired output frequency range such that a frequency upconverter is not needed to produce signals in the desired radio frequency range.

A reduced-complexity Internet of Things sensor is disclosed. An example apparatus comprises memory storing one or more sensor event messages, a radio configured to determine a sensor event, a counter configured to output incremental counter states, and a control circuitry. The control circuitry may be in communication with the memory, the radio, and counter, and the sensor. The control circuitry may be configured to determine, based on the sensor event, a select sensor event message of the one or more sensor event messages. The control circuitry may be further configured to output, via the radio signal, a packet comprising the select event message and an indication of a counter state associated with the sensor event message.

An apparatus comprising a local oscillator (LO) for driving a mixer, the LO being configured to oscillate at an oscillation frequency, and generate a first set of LO signals, wherein each of the first set of LO signals has a LO signal frequency equal to a first multiplication factor m multiplied by the oscillation frequency, the first multiplication factor m, being an integer greater than or equal to two, and each of the first set of LO signals is separated by adjacent LO signals by a phase difference equal to 360° divided by a first variable n, the first variable n being an integer that is greater than or equal to two.

A frequency multiplier includes an input section having inputs to receive an input signal having an input frequency, a mixer section, and an output section magnetically coupled to the input section and generating an output signal in response to the input signal. The mixer section may be coupled to the input section by a common mode node forming a path for a common mode current to flow to the mixer section and be magnetically coupled to the common mode node. The input section may generate a signal current, and the mixer section may be magnetically coupled to the input section and be directly capacitively coupled to the input section through a capacitor in a signal current path. The mixer section may have differential inputs capacitively coupled to the input section and also be coupled to the input section through a current path. A current helper section may be coupled to the current path.

A frequency multiplier includes an input section having inputs to receive an input signal having an input frequency, a mixer section, and an output section magnetically coupled to the input section and generating an output signal in response to the input signal. The mixer section may be coupled to the input section by a common mode node forming a path for a common mode current to flow to the mixer section and be magnetically coupled to the common mode node. The input section may generate a signal current, and the mixer section may be magnetically coupled to the input section and be directly capacitively coupled to the input section through a capacitor in a signal current path. The mixer section may have differential inputs capacitively coupled to the input section and also be coupled to the input section through a current path. A current helper section may be coupled to the current path.

A mixer for generating an analog output signal X.sub.OUT from an analog input signal X.sub.IN using a mixing signal having a mixing frequency f.sub.MIX, the mixer comprising: a scaler being configured to sample the analog input signal X.sub.IN at a plurality of discrete points in time k with a sampling frequency f.sub.S to obtain a sampled analog input signal X.sub.IN[k] having a continuous signal value, and to generate the analog output signal X.sub.OUT having a continuous signal value by scaling the sampled analog input signal X.sub.IN[k] on the basis of a plurality of scaling coefficients A[k], wherein the scaling coefficients A[k] are a time-discrete representation of the mixing signal.

In a communication system of the LPWAN type including a server and a plurality of gateways intended to make wireless communications with terminals in said communication system, the server: obtains a description of a mobility hierarchy in which mobility types are hierarchically defined; obtains a description of a mobility tree in which mobility areas are hierarchically defined, in conformity with the mobility hierarchy; obtains terrain measurements associated with each mobility area defined in the mobility tree; establishes a frequency plan on the basis of the mobility tree and terrain measurements; and configures the gateways and the terminals according to the frequency plan established.

Methods and apparatus for transmitting signals, the transmitter including a memory storing instructions and a controller configured to execute the instructions to cause the transmitter to determine whether a value of transmitter power is less than a threshold, responsive to a determination that the value of transmitter power is less than the threshold: mix a baseband signal with a first oscillator signal to produce a very-low intermediate frequency (VLIF) signal; mix the VLIF signal with a second oscillator signal to produce a radio frequency (RF) signal, and transmit the RF signal.