Patent classifications
H04L27/01
HIGH-SPEED SIGNALING SYSTEMS WITH ADAPTABLE PRE-EMPHASIS AND EQUALIZATION
A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.
HIGH-SPEED SIGNALING SYSTEMS WITH ADAPTABLE PRE-EMPHASIS AND EQUALIZATION
A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.
Receiver/transmitter co-calibration of voltage levels in pulse amplitude modulation links
A driver circuit of a PAM-N transmitting device transmits a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels corresponding to N symbols. A PAM-N receiving device receives the PAM-N signal. The PAM-N receiving device generates distortion information indicative of a level of distortion corresponding to inequalities in voltage differences between the N signal levels. The PAM-N receiving device transmits to the PAM-N transmitting device the distortion information indicative of the level of the distortion. The PAM-N transmitting device receives the distortion information. The PAM-N transmitting device adjusts one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.
Receiver/transmitter co-calibration of voltage levels in pulse amplitude modulation links
A driver circuit of a PAM-N transmitting device transmits a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels corresponding to N symbols. A PAM-N receiving device receives the PAM-N signal. The PAM-N receiving device generates distortion information indicative of a level of distortion corresponding to inequalities in voltage differences between the N signal levels. The PAM-N receiving device transmits to the PAM-N transmitting device the distortion information indicative of the level of the distortion. The PAM-N transmitting device receives the distortion information. The PAM-N transmitting device adjusts one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.
GEAR SHIFTING IN A SKYWAVE SYSTEM
A gear shifting technique has been developed in which modulation and equalization are shifted to achieve optional performance. In one form, two or more equalizers, each associated with a demodulator and message decoder, determine if the modulation being used can be increased in complexity in order to increase the channel throughput or determine if the modulation method should be reduced in complexity in order to improve the receiver error performance. The quality metrics can based on which equalizer-demodulator-decoder is set to first detect a valid message. Other factors can be considered with this technique such as a packet-error ratio and a signal-to-noise ratio. In a financial trading system, message erasures can be favored over errored messages by limiting the number of bit or symbol corrections permitted per message to less than the maximum possible for the selected decoding schemes.
GEAR SHIFTING IN A SKYWAVE SYSTEM
A gear shifting technique has been developed in which modulation and equalization are shifted to achieve optional performance. In one form, two or more equalizers, each associated with a demodulator and message decoder, determine if the modulation being used can be increased in complexity in order to increase the channel throughput or determine if the modulation method should be reduced in complexity in order to improve the receiver error performance. The quality metrics can based on which equalizer-demodulator-decoder is set to first detect a valid message. Other factors can be considered with this technique such as a packet-error ratio and a signal-to-noise ratio. In a financial trading system, message erasures can be favored over errored messages by limiting the number of bit or symbol corrections permitted per message to less than the maximum possible for the selected decoding schemes.
PAM-N receiver capable of adaptively adjusting threshold voltages determining level of data in received signal and method of adaptively adjusting threshold voltages of PAM-N receiver
A PAM-N receiver capable of adaptively adjusting threshold voltages determining a level of a received signal and a method of adaptively adjusting threshold voltages thereof are disclosed. According to the method of the present invention, the result of comparison between reference data levels and the level of data in the received signal are used to adjust the reference data levels, and the threshold voltages of a PAM-N receiver are adaptively calculated from the adjusted reference data levels, thereby reflecting transmission line conditions and Inter-Symbol Interference.
PAM-N receiver capable of adaptively adjusting threshold voltages determining level of data in received signal and method of adaptively adjusting threshold voltages of PAM-N receiver
A PAM-N receiver capable of adaptively adjusting threshold voltages determining a level of a received signal and a method of adaptively adjusting threshold voltages thereof are disclosed. According to the method of the present invention, the result of comparison between reference data levels and the level of data in the received signal are used to adjust the reference data levels, and the threshold voltages of a PAM-N receiver are adaptively calculated from the adjusted reference data levels, thereby reflecting transmission line conditions and Inter-Symbol Interference.
Method of receiving signal stream and a receiver
Embodiments of the present disclosure are related to a receiver and a method for receiving signal. The method comprises estimating, by a receiver, channel for each of a plurality of antennas using the received signal stream, to produce a plurality of estimated channels. Also, method comprises grouping a predetermined number of received signals from the received signal stream and estimated channels associated with the received signals to obtain a plurality of groups. Further, a group specific filtering is performed on the received signals and corresponding estimated channels of each of the plurality of groups to obtain filtered received signals and a plurality of filtered estimated channels. Thereafter, the method comprises performing second filtering on all the filtered received signals to produce second filtered signals, which are processed to produce an output.
Method of receiving signal stream and a receiver
Embodiments of the present disclosure are related to a receiver and a method for receiving signal. The method comprises estimating, by a receiver, channel for each of a plurality of antennas using the received signal stream, to produce a plurality of estimated channels. Also, method comprises grouping a predetermined number of received signals from the received signal stream and estimated channels associated with the received signals to obtain a plurality of groups. Further, a group specific filtering is performed on the received signals and corresponding estimated channels of each of the plurality of groups to obtain filtered received signals and a plurality of filtered estimated channels. Thereafter, the method comprises performing second filtering on all the filtered received signals to produce second filtered signals, which are processed to produce an output.