Patent ID: 11894911
Assignee: SANTANU DUTTA
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A system for communication comprising:
at least one fractionated satellite, the at least one fractionated satellite comprising a plurality of satellites, each of the plurality of satellites comprising:
an antenna;
a relative orbit location and
an absolute pointing direction,

wherein the antennas of the plurality of satellites form a phased array antenna,
wherein the phased array antenna are configured to establish uplink and downlink communication links with user equipment on a surface of the earth using synthesized uplink and downlink antenna patterns, and
wherein nulls of the synthesized uplink and down link patterns are placed on undesired co-frequency user equipment,
wherein:
the downlink antenna patterns are formed at the satellites, individually for each of a plurality of desired user equipment in the presence of a plurality of undesired use equipment sharing the same frequency and time with the desired user equipment,
the downlink antenna pattern creates a relatively high gain towards the desired user equipment and a relatively low gain towards the plurality of undesired user equipment such that a ratio of powers of desired and undesired signals at the fractionated satellite exceeds a desired value,
the downlink antenna patterns are formed based on using unique pilot signals transmitted by each satellite, and
the downlink antenna patterns are formed based on:
each user equipment computing a vector of downlink channel state estimates based on the unique pilot signals received from the plurality of satellites, the vector of downlink channel state estimates being identified by a time of receipt at the user equipment,
each user equipment transmitting the downlink channel state vectors back to the plurality of satellites using the uplink communication links from the user equipment to the satellites,
downlink channel state vectors corresponding to times of receipt within a coherence block being collected in an initial channel state matrix,
the initial channel state matrix being used to predict a predicted channel state matrix at a future time, identified by a scheduled transmit time, using a prediction algorithm,
an optimal weight vector is calculated for each of the plurality of user equipment, using an optimization method whose inputs include the predicted channel state matrix and a predicted channel state vector for the user equipment, wherein the predicted channel state vector is additionally provided by the prediction algorithm, and
form a downlink signal vector destined for each user equipment formed by calculating a scalar product between the optimal weight vector and a scalar user signal for the user equipment,

wherein the downlink signal vectors for a plurality of user equipment are linearly added to form a composite transmit vector and the composite transmit vector is transmitted using the phased array antenna of the fractionated satellite.