A communication device includes a sampler configured to sample an input signal, wherein the sampler is configured to generate a sampled value for each sampling time of a sequence of sampling times, a sequence value generator configured to generate an output value for each sampling time of the sequence of sampling times based on the sampled values, wherein the sequence value generator is configured to set the output value for a sampling time based on the sampled value for the sampling time and based on a limitation of the difference between the output value for the sampling time and the output value for the preceding sampling time in the sequence of sampling times, and an edge detector configured to detect an edge in the input signal based on the output values.

One or more link training signals are received, including instances of a link training pattern, on a plurality of lanes of a physical link that includes at least one valid lane and a plurality of data lanes. The plurality of lanes are trained together using the link training signals to synchronize sampling of the valid lane with sampling of the plurality of data lanes. An active link state is entered and a valid signal received on the valid lane during the active link state. The valid signal includes a signal held at a value for a defined first duration and indicates that data is to be received on the plurality of data lanes in a second defined duration subsequent to the first duration. The data is to be received, during the active link state, on the plurality of data lanes during the second defined duration.

In performing SVD-MIMO transmission, a set-up procedure is simplified while assuring a satisfactory decoding capability with a reduced number of antennas. A transmitter estimates channel information based on reference signals sent from a receiver, determines a transmit antenna weighting coefficient matrix based on the channel information, calculates a weight to be assigned to each of components of a multiplexed signal, and sends, to the receiver, training signals for respective signal components, the training signals being weighted by the calculated weights. On the other hand, the receiver determines a receive antenna weighting coefficient matrix based on the received training signals.

A primary transmitter of a multicast communication system transmits in-band backhaul to a relay transmitter using an LDM signal that also carries services to end-users. The relay transmitter processes received wireless signal to extract the in-band backhaul and re-transmits services obtained from the in-band backhaul in same or different frequency channel. The in-band backhaul may be transmitted in a high-capacity layer of the LDM signal carrying or in a separate timeslot. Transmitter-specific signature signals may be used for loopback and forward channel estimation at the relay transmitter. The in-band backhaul may also carry service data for devices in a different network.

A transmitter for transmitting an output signal includes first and second filter structures. The first filter structure includes a first combiner to extend a first data signal by a first reference signal to obtain a first extended data signal, and a first IIR filter for filtering the first extended data signal to obtain a first filtered data signal. The second filter structure includes a second combiner to extend a second data signal by a second reference signal, and a second IIR filter for filtering the second extended data signal. The transmitter includes a multiplexer for combining the first and second filtered data signals to obtain the output signal. A system response of the first IIR filter based on the first reference signal corresponds to a system response of the second IIR filter based on the second reference signal.

A system and method are described for distributed antenna wireless communications. For example, a method implemented within a wireless transmission system comprised of a plurality of wireless client devices and a plurality of distributed antennas is described comprising: computing channel state information (CSI) for wireless communication channels between the plurality of base distributed antennas and the wireless client devices; computing precoding weights from the channel state information; precoding data using the precoding weights prior to wireless transmission from the plurality of distributed antennas to the wireless client devices; and wirelessly transmitting the precoded data from the distributed antennas to each of the wireless client devices, wherein the precoding causes radio frequency interference between the plurality of base stations but simultaneously generating a plurality of non-interfering radio frequency user channels between the plurality of distributed antennas and the plurality of wireless client devices.

A target constellation diagram determining method, a data sending method, and an apparatus are provided in accordance with the disclosure. The target constellation diagram determining method in accordance with the disclosure may include receiving, by a receiving device, training data that is generated and sent by a sending device based on each constellation point in an alternative constellation diagram. A detection region of each constellation point can then be determined based on a position of the training data in the alternative constellation diagram. A cumulative distance corresponding to the alternative constellation diagram can be obtained based on a distance between the detection regions of the constellation points. The method may include determining, based on cumulative distances corresponding to a plurality of alternative constellation diagrams, that an alternative constellation diagram with a largest cumulative distance is a target constellation diagram, and notifying the sending device of the target constellation diagram, so that the sending device modulates to-be-sent data based on the target constellation diagram.

A training packet sending method and apparatus, where the method includes generating, by a first device, a training packet, where the training packet includes a preamble, a header, and a training field, and the header includes at least a legacy header, and repeatedly sending, by the first device, the preamble using N channels, sending the legacy header in the header using the N channels, and sending the training field to at least one second device using H channels of the N channels, where N is greater than 1, and H is greater than 1 and less than or equal to N.

The present disclosure is directed to systems, apparatuses, and methods for performing continuous or periodic link training. Existing link training protocols generally perform link training only once during startup or initialization of a link and, as a result, are limited in their applications. After link training is performed and Open Systems Interconnect (OSI) data link layer and other high-layer data is transmitted across the link, no further link training is performed using these existing link training protocols. However, parameters of the link may change over time after link training is performed, such as temperature of the link and voltage levels of signals transmitted over the link by the transmitter of the transmitter-receiver pair.

The present disclosure is directed to systems, apparatuses, and methods for performing continuous or periodic link training. Existing link training protocols generally perform link training only once during startup or initialization of a link and, as a result, are limited in their applications. After link training is performed and Open Systems Interconnect (OSI) data link layer and other high-layer data is transmitted across the link, no further link training is performed using these existing link training protocols. However, parameters of the link may change over time after link training is performed, such as temperature of the link and voltage levels of signals transmitted over the link by the transmitter of the transmitter-receiver pair.