A system includes a transmit equalizer to equalize a data stream using a set of transmit parameters to generate an input signal. The system further includes a communication channel to receive the input signal. The system further includes a receive equalizer to receive an output signal from the communication channel in response to the input signal and detect the data stream from the output signal using a set of receive parameters. The system additionally includes a controller to change the set of transmit parameters in response to a condition, where the transmit parameters, the receive parameters, and the condition are selected to both enable the receive equalizer to detect the data stream from the output signal and reduce the likelihood of an external circuit detecting the data stream from the output signal.

Provided are a data transmission method and apparatus, an electronic device, and a storage medium. The data transmission method includes following steps: a sequence 1 is inserted in front of each first data sequence among L to-be-transmitted first data sequences and a sequence 2 is inserted behind each first data sequence so that L second data sequences are formed, where L is an integer greater than or equal to 2, the sequence 1 includes M sequences 3, the sequence 2 includes N sequences 3, each of M and N is an integer greater than 0, and a sequence 3 satisfies that KT.sub.3=T.sub.cp, where T.sub.3 denotes the time length of a time domain of the sequence 3, K is an integer greater than 0 and less than or equal to N, and T.sub.cp denotes the time length of a cyclic prefix; and the L second data sequences are transmitted.

A digital down-converter with baseband equalization comprises a composite analog-to-digital converter (ADC) adapted to convert an applied RF analog signal to be processed to a digital signal, and then down-convert the digital signal to a baseband frequency region, and then perform equalization on the down-converted digital signal, thereby reducing distortions caused by introduction of spurious signals by the ADC.

A processing module for a transmitter device configured to provide for generation of a signal comprising at least one frame for transmission by the transmitter device to a receiver device, the processing module configured to provide for processing of an input pulse stream comprising a stream of pulses representative of data, to provide an output pulse stream, each pulse of the pulse streams having one of two states defining the phase with which a carrier wave is modulated; the processing module configured to; divide the input pulse stream into consecutive groups of pulses; and for each group of pulses, based on determination that the first two or more consecutive pulses of the group have the same polarity, provide for addition of at least one dummy pulse to the group directly after the first two or more consecutive pulses, with an opposite polarity.

The present invention provides for an improved application of signal strength weightings in a SDMA sectorized cellular network. The improved signal strength weightings application is conducted through the improved selection of weightings from a new codebook subset or by the selection of weightings from a larger codebook subset. In a further embodiment, an antenna beam index or bit map can be used to select the best beam(s) in a SDMA sectorized cellular network. In another embodiment, a field or factor in an uplink or downlink transmission packet can designate which directional transmission beam is best suited for the transmission or when the directional transmission beam should be activated.

A system includes a transmit equalizer to equalize a data stream using a set of transmit parameters to generate an input signal. The system further includes a communication channel to receive the input signal. The system further includes a receive equalizer to receive an output signal from the communication channel in response to the input signal and detect the data stream from the output signal using a set of receive parameters. The system additionally includes a controller to change the set of transmit parameters in response to a condition, where the transmit parameters, the receive parameters, and the condition are selected to both enable the receive equalizer to detect the data stream from the output signal and reduce the likelihood of an external circuit detecting the data stream from the output signal.

A system includes a transmit equalizer to equalize a data stream using a set of transmit parameters to generate an input signal. The system further includes a communication channel to receive the input signal. The system further includes a receive equalizer to receive an output signal from the communication channel in response to the input signal and detect the data stream from the output signal using a set of receive parameters. The system additionally includes a controller to change the set of transmit parameters in response to a condition, where the transmit parameters, the receive parameters, and the condition are selected to both enable the receive equalizer to detect the data stream from the output signal and reduce the likelihood of an external circuit detecting the data stream from the output signal.

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.

One feature pertains to an apparatus that includes a first stage track and hold circuit that subsamples a receive equalizer output of a receive equalizer, and a second stage track and hold circuit that generates a first signal representative of an average voltage value of a logical value at the receive equalizer output when a high frequency bit pattern is detected, and a second signal representative of an average voltage value of the logical value at the receive equalizer output when a steady state bit pattern is detected. The apparatus further includes a comparator circuit that generates a comparator output signal that indicates which of the first signal and the second signal has a greater magnitude, and a processing circuit that generates equalizer tuning signals based on the comparator output signal to adjust parameters of an equalizer that affects the receive equalizer output.

A communication apparatus has a receiver that is capable of receiving an alternating phase signal and a tuned circuit whose input is adjusted to be capable of receiving the alternating phase signal. The communication apparatus can be used with both wireless and wired communication links and provide enable faster data rates, greater immunity to noise, increased bandwidth/spectrum efficiency and/or other benefits. Applications include but are not limited to: cell phones, smartphones (e.g., iPhone, BlackBerry, etc.), wireless Internet, local area networks (e.g., WiFi type applications), wide area networks (e.g., WiMAX type applications), personal digital assistants, computers, Internet service providers and communications satellites.