An intelligent backhaul radio that has an advanced antenna system for use in PTP or PMP topologies. The antenna system provides a significant diversity benefit. Antenna configurations are disclosed that provide for increased transmitter to receiver isolation, adaptive polarization and MIMO transmission equalization. Adaptive optimization of transmission parameters based upon side information provided in the form of metric feedback from a far end receiver utilizing the antenna system is also disclosed.

The implementations allow increases in data rate provided by the Faster-Than-Nyquist multi-carrier signaling to he balanced against system conditions to maintain transmission error rates on channels within an acceptable range. If conditions such as channel traffic load, inter-system interference, intra-system interference, available transmission power, and/or available bandwidth change, the Faster-Than-Nyquist multi-carrier signaling acceleration factor used on system channels may be adjusted based on the changing conditions. If conditions change unfavorably, the acceleration factor may be increased to lower the data rate so that the error rate improves on the one or more channels. If conditions change favorably, the acceleration factor may be decreased to increase the data rate in the improved channel conditions. During system operation, channel conditions may be monitored, and the acceleration factor on the channels may be adjusted to provided higher or lower data rates according to any changes in the channel conditions.

The present application relates to a filtering scheme with low complexity. The method includes: dividing an orthogonal frequency division multiplexing (OFDM) signal into a first sideband signal, a first signal, and a second sideband signal; sampling the first sideband signal by using a first sampling rate; sampling the first signal by using a second sampling rate; sampling the second sideband signal by using a third sampling rate; and separately performing filtering processing of a third spectral mask, upsampling processing, and digital frequency conversion processing to generate a first filtered-OFDM (f-OFDM) signal, a second f-OFDM signal and a third f-OFDM signal; and superposing the first f-OFDM signal, the second f-OFDM signal, and the third f-OFDM signal to obtain an f-OFDM signal, where the first sampling rate and the third sampling rate are both less than the second sampling rate.

The present invention relates to a 5th-generation (5G) or pre-5G communication system, which is to be provided for supporting a higher data transmission rate after the 4th-generation (4G) communication system, such as long term evolution (LTE). The present invention provides a method for receiving a signal in a multi-carrier system, the method comprising the steps of: performing, with respect to an input signal, a waveform pre-processing operation on the basis of at least one of an equalizing operation and a filtering operation; checking whether the waveform pre-processed signal is a Gaussian proximity signal; and performing soft-de-mapping with respect to the waveform pre-processed signal on the basis of a result of the checking.

A method for transmitting a signal is described, wherein the method has transforming a signal into a frequency domain to obtain a spectrum, forming a filtered spectrum according to a filter spectrum and occupying a set of subcarriers of a frequency domain representation of an Orthogonal Frequency Division Multiplex (OFDM) signal with the filtered spectrum. A temporary signal is obtained by transforming the frequency domain representation of the OFDM signal into a time domain. The temporary signal is subjected to a phase modulation.

Apparatus and methods related to multipath bandpass filters with passband notches are provided herein. In certain configurations, a multipath bandpass filter includes multiple filter circuit branches or paths that are electrically connected in parallel with one another between an input terminal and an output terminal. The input terminal receives an input signal, and each filter circuit branch includes a downconverter that downconverts the input signal to generate a downconverted signal, a filter network that generates a filtered signal by filtering the downconverted signal, and an upconverter that upconverts the filtered signal to generate a branch output signal. The filter network includes at least one low pass filter and at least one notch filter to provide a passband with in-band notches. The branch output signals from the filter circuit branches are combined to generate an output signal at the output terminal.

Multipath filters are provided herein. In certain configurations, a multipath filter includes multiple filter paths or circuit branches that are electrically connected in parallel with one another between an input terminal and an output terminal. The input terminal receives an input signal, and each filter circuit branch includes a double-in double-switched (DIDS) downconverter that downconverts the input signal with two different clock signal phases to generate a downconverted signal. Each filter circuit branch further includes a filter network that generates a filtered signal by filtering the downconverted signal and an upconverter that upconverts the filtered signal to generate a branch output signal. Additionally, the branch output signals from the filter circuit branches are combined to generate an output signal at the output terminal.

Methods, systems, and devices for wireless communications are described. A transmitting device may filter data tones (e.g., in edge subbands of an allocated frequency band) to achieve time domain windowing or shaping. Data tones of edge subbands of a configured frequency band may be filtered to shape a waveform such that it does not extend beyond symbol boundaries (e.g., does not result in emission leakage). In some examples, the transmitter may provide an indication of subband frequency domain shaping filters used to the receiver, to support demodulation on the receiver side. In some examples, the transmitter may indicate a demodulation reference signal (DMRS) comb structure (e.g., of the edge subbands) to the receiver, and the receiver may determine or estimate the filters of the subband frequency domain shaping based on the comb structure or the indication of the filters.

Techniques and apparatus for optimizing transmitter equalization are described. An example technique includes capturing a single output signal transmitted from a port on at least one channel of a host device. An impulse response of the channel is determined based at least in part on the single output signal. A transmitter feedforward equalization (FFE) is generated, based at least in part on the impulse response of the channel. The transmitter FFE is applied to the channel of the port of the host device.

A method is provided for transmitting a sequence of data symbols including at least two data symbols of distinct values, delivering an electromagnetic wave carrying an orbital angular momentum. The method includes, for at least one data symbol to be transmitted: a bijective selection of an order of orbital angular momentum associating, with each distinct value of a data symbol, a distinct order of orbital angular momentum, and delivering a selected order of orbital angular momentum that is representative, by bijection, of the value of the at least one data symbol to be transmitted; and transmitting the electromagnetic wave carrying an orbital angular momentum, the order of orbital angular momentum of which corresponds to the selected order of orbital angular momentum.