A method for transmitting and receiving a broadcast signal by an access network to a plurality of terminals of a two-way wireless communication system. An information signal is formed from the broadcast information destined for the terminals. A pilot signal is formed and a broadcast signal including the information signal SI1 and the pilot signal is transmitted. The information signal and the pilot signal are transmitted on different respective central frequencies having a predefined frequency gap.

A polar transmitter includes an amplitude path comprising an amplitude signal that corresponds to an amplitude of a vector sum of an in-phase input signal and a quadrature input signal; a phase path comprising a phase modulator configured to phase-modulate a phase signal that corresponds to the phase of the vector sum of the in-phase input signal and the quadrature input signal; a digital power amplifier (DPA) configured to amplify the phase-modulated (PM) input signal based on the amplitude signal; a tunable matching network coupled to an output of the DPA and configured to adjust a load impedance of the DPA; and a controller configured to adjust the matching network based on a look-up table with respect to amplitude and frequency information, where the look-up table indicates a plurality of optimal operation modes of the matching network for specific combinations of amplitude and frequency information.

Disclosed are methods, systems, devices, apparatus, media, design structures, and other implementations, including a method for digital predistortion of multiband signals that includes receiving a plurality of input signals respectively associated with multiple radio frequency (RF) bands, with the plurality of input signals occupying an input frequency span corresponding to a difference between a maximum frequency in a highest of the multiple RF bands and a minimum frequency in a lowest of the multiple RF bands. The method further includes frequency shifting at least one signal from the plurality of input signals to produce condensed shifted signals, each corresponding to a respective one of the plurality of input signals, occupying a condensed frequency span smaller than the input frequency span, and processing the condensed shifted signals, including applying digital predistortion to the condensed shifted signals.

Certain aspects of the present disclosure are directed to a digital predistortion (DPD) device for use within a wireless transmitter that permits the use of a downstream digital-to-analog converter that operates at a clock rate close to the bandwidth of a digital baseband input signal. In some examples, a sampling rate of a digital baseband input signal is increased using an upsampler to obtain an increased rate digital input signal. Predistortion is applied to the increased rate digital input signal using a DPD device to obtain a predistorted digital signal. The sampling rate of the predistorted digital signal is then decreased using a downsampler to obtain a lower-rate predistorted digital signal with a sampling rate below the increased rate of the upsampler (e.g. close to the bandwidth of a digital baseband input signal). A low pass filter may be provided to filter out-of-band signal components from the predistorted digital signal.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

A method of operating a communications system includes receiving a signal at a digital predistorter (DPD), introducing predistortion to the signal using the DPD, and converting the predistorted signal to an analog signal using a digital-to-analog converter having a first bandwidth. The method also includes amplifying the analog signal, sampling the amplified signal using an analog-to-digital converter having a second bandwidth less than the first bandwidth, and extracting coefficients of the DPD from the sampled signal..

A method for determining a noise shaped quantized parameter contributing to generation of an output signal comprises estimating an error within the output signal using a quantization of the parameter and a quantization of a further parameter contributing to generation of the output signal. The quantization of the parameter is used as the noise shaped quantized parameter according to a selection criterion.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

A network node may transmit a training signal for a UE on a plurality of sub-carriers, the training signal transmitted via multiple IQ modulators and multiple RF antenna panels and receive a feedback associated with an FDRSB based on the training signal. The network node may apply an FDRSB correction filter to at least one signal to be transmitted to the UE, and the FDRSB correction filter may be based on the feedback received from the UE. The training signal may include at least one tone transmitted on a first subset of sub-carriers of the plurality of sub-carriers, the first subset of sub-carriers being configured symmetric to a second subset of sub-carriers with respect to a center frequency of the plurality of sub-carriers, and the second subset of sub-carriers being free of the at least one tone of the training signal.

A network node may transmit a training signal for a UE on a plurality of sub-carriers, the training signal transmitted via multiple IQ modulators and multiple RF antenna panels and receive a feedback associated with an FDRSB based on the training signal. The network node may apply an FDRSB correction filter to at least one signal to be transmitted to the UE, and the FDRSB correction filter may be based on the feedback received from the UE. The training signal may include at least one tone transmitted on a first subset of sub-carriers of the plurality of sub-carriers, the first subset of sub-carriers being configured symmetric to a second subset of sub-carriers with respect to a center frequency of the plurality of sub-carriers, and the second subset of sub-carriers being free of the at least one tone of the training signal.