Systems and methods for wireless communication with per-beam signal synchronization

A method for per-beam signal synchronization comprising, during wireless communication between a signal transmitting device and a signal receiving device:

• receiving, by the signal receiving device, a beam domain signal via a beam set from the signal transmitting device;
• and
• individually synchronizing, by the signal receiving device the beam domain signal in each beam of the beam set, wherein the individually synchronizing of the beam domain signal further comprises, for the beam domain signal of each individual beam of the plurality beams;
• determining a target frequency adjustment based on frequency offset of the beam domain signal when the beam domain signal is transmitted to the signal receiving device;
• and
• adjusting at least one frequency independent variable of the beam domain signal by the target frequency adjustment,
• wherein the beam domain signal of each beam comprises a plurality of transmission blocks, and wherein the determining of the target frequency adjustment further comprises:
• for each of the plurality of transmission blocks,
• determining a candidate minimum frequency adjustment as a minimum frequency offset of the beam domain signal induced to the beam;
• determining a candidate maximum frequency adjustment as a maximum frequency offset of the beam domain signal induced to the beam;
• determining a lower bound value of the target frequency adjustment as the minimum of the plurality of the candidate minimum frequency adjustments;
• determining an upper bound value of the target frequency adjustment as the maximum of the plurality of the candidate maximum frequency adjustments;
• and
• selecting a value of the target frequency adjustment between the lower bound value and upper bound value.

A signal transmitting electronic device, comprising:

• at least one storage medium including a set of instructions for per-beam signal synchronization;
• and
• at least one processor in communication with the at least one storage medium, wherein when executing the set of instructions, the processor is directed to conduct a wireless communication with a signal receiving device via beamforming, during which the at least one processor is directed to:
• determine a beam set to send beam domain signals to the signal receiving device;
• for a beam domain signal of each individual beam of the beam set,
• individually synchronize the beam domain signal in each beam of the beam set;
• and
• send the beam domain signal to the signal receiving device, wherein to individually synchronize the beam domain signal in each of the plurality of beams, the at least one processor is further directed to:
• determine a target frequency adjustment based on frequency offset of the beam domain signal that will be induced when the beam domain signal is transmitted to the signal receiving device;
• and
• adjust at least one frequency independent variable of the beam domain signal by the target frequency adjustment,
• wherein the beam domain signal of each beam comprises a plurality of transmission blocks, and wherein to determine the target frequency adjustment, the processor is further directed to:
• for each of the plurality of transmission blocks,
• determine a candidate minimum frequency adjustment as a minimum frequency offset of the beam domain signal that will be induced to the beam;
• determine a candidate maximum frequency adjustment as a maximum frequency offset of the beam domain signal that will be induced to the beam;
• determine a lower bound value of the target frequency adjustment as the minimum of the plurality of the candidate minimum frequency adjustments;
• determine an upper bound value of the target frequency adjustment as the maximum of the plurality of the candidate maximum frequency adjustments;
• and
• select a value of the target frequency adjustment between the lower bound value and upper bound value.

A method for per-beam signal synchronization comprising, during wireless communication between a signal transmitting device and a signal receiving device:

• determine, by the signal transmitting device, a beam set to send beam domain signals to the signal receiving device;
• for a beam domain signal of each individual beam of the beam set,
• individually synchronizing, by the signal transmitting device, the beam domain signal in each beam of the beam set;
• and
• sending, by the signal transmitting device, the beam domain signal to the signal receiving device, wherein the individually synchronizing of the beam domain signal in each of the plurality of beams further comprises:
• determining a target frequency adjustment based on frequency offset of the beam domain signal that will be induced when the beam domain signal is transmitted to the signal receiving device;
• and
• adjusting at least one frequency independent variable of the beam domain signal by the target frequency adjustment,
• wherein the beam domain signal of each beam comprises a plurality of transmission blocks, and wherein the determining of the target frequency adjustment, the processor is further directed to:
• for each of the plurality of transmission blocks,
• determining a candidate minimum frequency adjustment as a minimum frequency offset of the beam domain signal that will be induced to the beam;
• determining a candidate maximum frequency adjustment as a maximum frequency offset of the beam domain signal that will be induced to the beam;
• determining a lower bound value of the target frequency adjustment as the minimum of the plurality of the candidate minimum frequency adjustments;
• determining an upper bound value of the target frequency adjustment as the maximum of the plurality of the candidate maximum frequency adjustments;
• and
• selecting a value of the target frequency adjustment between the lower bound value and upper bound value.

A beam division multiple access (BDMA) based massive multiple-input multiple-output (MIMO) downlink transmission method with per-beam time/frequency synchronization, comprising:

• performing beamforming at both base stations and user terminals by dividing channels in space, wherein both the base stations and the user terminals are equipped with antenna arrays, and wherein the numbers of beams formed at the base stations and the user terminals are several or several dozens;
• performing synchronization of transmission signals in BDMA over each beam individually in beam sets of the user terminals, wherein each user terminal estimates the time/frequency adjustment parameters of the signals over each beam individually based on the received synchronization signals sent from the base stations, wherein performing synchronization of the transmission signals in BDMA over each beam individually in the beam sets of the user terminals comprises, for a beam domain signal of each individual beam in the beam sets of the user terminals:
• determining a target frequency adjustment based on frequency offset of the beam domain signal when the beam domain signal is transmitted to the user terminals;
• and
• adjusting at least one frequency independent variable of the beam domain signal by the target frequency adjustment,
• wherein the beam domain signal of each beam comprises a plurality of transmission blocks, and wherein the determining of the target frequency adjustment further comprises:
• for each of the plurality of transmission blocks,
• determining a candidate minimum frequency adjustment as a minimum frequency offset of the beam domain signal induced to the beam;
• determining a candidate maximum frequency adjustment as a maximum frequency offset of the beam domain signal induced to the beam;
• determining a lower bound value of the target frequency adjustment as the minimum of the plurality of the candidate minimum frequency adjustments;
• determining an upper bound value of the target frequency adjustment as the maximum of the plurality of the candidate maximum frequency adjustments;
• and
• selecting a value of the target frequency adjustment between the lower bound value and upper bound value;
• at the user terminals, applying time/frequency synchronization to received signals based on the estimates of the time/frequency adjustment parameters over each receive beam individually;
• at the base stations, performing beam and user scheduling to select user terminals that communicate with the base stations over the same time/frequency resources and the corresponding transmit beams for each user terminal based on beam domain channel statistics or partial information, wherein the base station beam sets assigned to different scheduled user terminals are mutually non-overlapping;
• and
• from the base stations, transmitting the pilot signals and data signals over the assigned beams for each scheduled user terminal wherein each scheduled user terminal applies per-beam time/frequency synchronization to the received signal over the receive beams;
• pilot signals are not required to be orthogonal for different user terminals,
• wherein BDMA based massive MIMO downlink wireless transmission is dynamically adjusted when the statistics or partial information of the channels between the base stations and the user terminals vary.

A beam division multiple access (BDMA) based massive multiple-input multiple-output (MIMO) uplink transmission method with per-beam time/frequency synchronization, comprising:

• performing beamforming at both base stations and user terminals by dividing channels in space, wherein both the base stations and the user terminals are equipped with antenna arrays, and wherein the numbers of beams formed at the base stations and the user terminals are several or several dozens;
• performing synchronization of transmission signals in BDMA over each beam individually in beam sets of the user terminals, wherein each user terminal estimates the time/frequency adjustment parameters of the signals over each beam individually based on the received synchronization signals sent from the base stations, wherein performing synchronization of the transmission signals in BDMA over each beam individually in the beam sets of the user terminals comprises, for a beam domain signal of each individual beam in the beam sets of the user terminals;
• determining a target frequency adjustment based on frequency offset of the beam domain signal when the beam domain signal is transmitted to the user terminals;
• and
• adjusting at least one frequency independent variable of the beam domain signal by the target frequency adjustment,
• wherein the beam domain signal of each beam comprises a plurality of transmission blocks, and wherein the determining of the target frequency adjustment further comprises:
• for each of the plurality of transmission blocks,
• determining a candidate minimum frequency adjustment as a minimum frequency offset of the beam domain signal induced to the beam;
• determining a candidate maximum frequency adjustment as a maximum frequency offset of the beam domain signal induced to the beam;
• determining a lower bound value of the target frequency adjustment as the minimum of the plurality of the candidate minimum frequency adjustments;
• determining an upper bound value of the target frequency adjustment as the maximum of the plurality of the candidate maximum frequency adjustments;
• and
• selecting a value of the target frequency adjustment between the lower bound value and upper bound value;
• at the user terminals, applying time/frequency synchronization to the transmit signals based on the estimates of the time/frequency adjustment parameters over each transmit beam individually;
• at the base stations, performing beam and user scheduling to select user terminals that communicate with the base stations over the same time/frequency resources and the corresponding receive beams for each user terminal based on beam domain channel statistics or partial information;
• and
• at the selected user terminals, applying per-beam time/frequency synchronization to the transmit pilot and data signals over the transmit beams, wherein the base stations process the signals over the assigned receive beams, and wherein pilot signals sent from different user terminals are not required to be orthogonal,
• wherein BDMA based massive MIMO uplink wireless transmission is dynamically adjusted when the statistics or partial information of the channels between the base stations and the user terminals vary.