A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

This document describes techniques for configuring beamformed wireless communication between a base station (121) and a user equipment (110) for grant-free communication using non-orthogonal multiple access (NOMA). In aspects, a base station (121) transmits downlink reference signals to a user equipment (110) using multiple transmit antenna configurations (402), configures multiple time-frequency resources for NOMA transmission by the user equipment (110) (404), and configures an association between the downlink reference signals and the time-frequency resources for the user equipment (110) (406). The base station (121) transmits the configuration of the time-frequency resources and the association between the downlink reference signals and the time-frequency resources to the user equipment (110) (408). The base station (121) receives uplink data from the user equipment (110) on one of the time-frequency resources using a receive antenna configuration, determined, at least in part, using one of the transmit antenna configurations (410).

This document describes techniques for configuring beamformed wireless communication between a base station (121) and a user equipment (110) for grant-free communication using non-orthogonal multiple access (NOMA). In aspects, a base station (121) transmits downlink reference signals to a user equipment (110) using multiple transmit antenna configurations (402), configures multiple time-frequency resources for NOMA transmission by the user equipment (110) (404), and configures an association between the downlink reference signals and the time-frequency resources for the user equipment (110) (406). The base station (121) transmits the configuration of the time-frequency resources and the association between the downlink reference signals and the time-frequency resources to the user equipment (110) (408). The base station (121) receives uplink data from the user equipment (110) on one of the time-frequency resources using a receive antenna configuration, determined, at least in part, using one of the transmit antenna configurations (410).

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter. A second one of the subcarriers carries third information that is not TDMA encoded, the third information being associated with a third node remote from the transmitter. A receiver and system also are described.

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter. A second one of the subcarriers carries third information that is not TDMA encoded, the third information being associated with a third node remote from the transmitter. A receiver and system also are described.

Secure channel training to enhance the confidentiality level of a power domain non-orthogonal multiple access (NOMA) communication system when impaired by eavesdropping attacks coming from inside and outside of the network. In a first scenario, a cooperative jammer available in the system defines an external source of entropy that is independent of the channel variation rate. While the jammer provides secrecy inside the network, the proposed invention is configured to secure the network from outside, encoding the system information, which is exchanged during the training phase, using only the channel state. In a second scenario, the cooperative jammer is not available; with the secrecy inside and outside of the network ensured through a different parameterization. That parameterization is done in a way that the required system information is encoded using not only the channels, but also a random phase defined in the data communication phase.

Provided are a QR decomposition-based detection method and apparatus based on overlapped multiplexing. The QR decomposition-based detection method includes: step S1: obtaining a receive sequence, where the receive sequence is a sequence obtained by encoding and modulating an input signal based on a multiplexing waveform matrix and transmitting the signal through a Gaussian channel; and step S2: detecting the receive sequence by using a QR decomposition algorithm, where step S2 includes: decomposing a foreknown multiplexing waveform matrix into a unitary matrix and an upper triangular matrix; performing matrix multiplication processing on the receive sequence based on the unitary matrix, to obtain a data sequence; and performing layer-by-layer detection on the data sequence based on the data sequence, the upper triangular matrix, and a quantized decision factor.

Provided are a QR decomposition-based detection method and apparatus based on overlapped multiplexing. The QR decomposition-based detection method includes: step S1: obtaining a receive sequence, where the receive sequence is a sequence obtained by encoding and modulating an input signal based on a multiplexing waveform matrix and transmitting the signal through a Gaussian channel; and step S2: detecting the receive sequence by using a QR decomposition algorithm, where step S2 includes: decomposing a foreknown multiplexing waveform matrix into a unitary matrix and an upper triangular matrix; performing matrix multiplication processing on the receive sequence based on the unitary matrix, to obtain a data sequence; and performing layer-by-layer detection on the data sequence based on the data sequence, the upper triangular matrix, and a quantized decision factor.