A wireless RF data transmission system has at least one base station transmitting control information on a control channel and high speed data on at least one data channel. At least one subscriber station receives the control information and data channels, adjusting a modulation and/or coding of reception of the data in response to the control information. Preferably, the control information is transmitted using a more robust modulation, such as QPSK, than used to transmit the data, which is preferably transmitted using either 16, 64 or 256 QAM. Additionally, timing or header information for the data may be included on the control channel.

Methods to improve the data carrying capacity of CATV DOCSIS systems and other communications systems are disclosed. Communications channels may be more efficiently spaced with reduced or absent guard bands by using receivers with adaptive signal cancellation methods, equalizing circuits, or polyphase filter banks and Fast Fourier Transform signal processing methods to correct for higher levels of cross-talk. QAM type communications channels may also be utilized on a synchronized two-transmitter at a time basis by adjusting the transmitters to predefined signal levels, such as +1, −1, +½, −½ to enable the combined signals to be distinguished at the receiver. These two methods may be combined to create a still higher data throughput system.

Methods to improve the data carrying capacity of CATV DOCSIS systems and other communications systems are disclosed. Communications channels may be more efficiently spaced with reduced or absent guard bands by using receivers with adaptive signal cancellation methods, equalizing circuits, or polyphase filter banks and Fast Fourier Transform signal processing methods to correct for higher levels of cross-talk. QAM type communications channels may also be utilized on a synchronized two-transmitter at a time basis by adjusting the transmitters to predefined signal levels, such as +1, −1, +½, −½ to enable the combined signals to be distinguished at the receiver. These two methods may be combined to create a still higher data throughput system.

A sonar includes a first part and a second part linked by an electric carrier cable configured to mechanically support the second part and allow the two parts of the sonar to exchange signals comprising: a unidirectional signal, called electrical power supply signal, unidirectional signals, called signals to be emitted, transmitted by the first part to the second part for them to be transmitted in the form of acoustic waves, and a bidirectional signal conveying communication data, the sonar wherein the first part comprises signal combination means configured for the signals to be transmitted simultaneously over the electric carrier cable, and in that the second part comprises separation means allowing the recovery of each of the signals transmitted over the electric carrier cable.

A data reception device that can improve communication quality when transmitting/receiving serial data is to be provided. There is provided the data reception device including a signal generation unit that generates, from serial data received, a first signal whose value is inverted at a rising timing of the serial data and a second signal whose value is inverted at a falling timing of the serial data, and a clock recovery unit that performs clock recovery using the first signal and the second signal generated by the signal generation unit.

Provided are a synchronization signal transmission method, a transmitting end device and a receiving end device. A frequency domain candidate position (also called SS raster) of a synchronization signal on an unlicensed frequency band is designed, the complexity of initial cell search is reduced, and the impact, on the other channels in a subband, of the position of the initial access of a cell in the unlicensed frequency band to a synchronization signal block in the subband is also reduced. The method comprises: a transmitting end device sending a synchronization signal block at a first frequency domain position, wherein the first frequency domain position is located at a frequency domain candidate position of a synchronization signal, and each 20 MHz subband comprises at least one of the synchronization signal frequency domain candidate positions.

Provided are a synchronization signal transmission method, a transmitting end device and a receiving end device. A frequency domain candidate position (also called SS raster) of a synchronization signal on an unlicensed frequency band is designed, the complexity of initial cell search is reduced, and the impact, on the other channels in a subband, of the position of the initial access of a cell in the unlicensed frequency band to a synchronization signal block in the subband is also reduced. The method comprises: a transmitting end device sending a synchronization signal block at a first frequency domain position, wherein the first frequency domain position is located at a frequency domain candidate position of a synchronization signal, and each 20 MHz subband comprises at least one of the synchronization signal frequency domain candidate positions.

Automatic Gain Control (AGC) system for multi-channel signals attenuates an incoming multi-channel signal by providing a gain. The system further adjusts each individual channel, of the multi-channel signal, by supplying a second gain if needed. The AGC system is designed to ensure a received signal power is at an optimal level for analog to digital conversion or any other form of signal processing. The system also enables elimination of mid-packet gain adjustments.

Automatic Gain Control (AGC) system for multi-channel signals attenuates an incoming multi-channel signal by providing a gain. The system further adjusts each individual channel, of the multi-channel signal, by supplying a second gain if needed. The AGC system is designed to ensure a received signal power is at an optimal level for analog to digital conversion or any other form of signal processing. The system also enables elimination of mid-packet gain adjustments.

A radio frequency (RF) communications system may include an RF transmitter having multicarrier transmitter circuitry that transmits frequency bands over a frequency range. A controller may selectively transmit real information over at least one of the frequency bands and selectively transmits fake information within the frequency range. The controller's operation is based on embedded machine learning model and real-time effectiveness feedback from built-in spectral analyzer. An RF receiver receives the real information from the RF transmitter.