| 摘要 |
Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using OTFS pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy OTFS data transmission methods. |
| 主权项 |
1. An automated method of acquiring a 2D channel state of an impaired data channel connecting at least one transmitter and at least one receiver,
said impaired data channel comprising at least one reflector, each said at least one reflector comprising a reflector location, reflector frequency shift, and at least one reflector coefficients of reflection; each said at least one transmitter comprising a transmitter location and transmitter frequency shift; each said at least one receiver comprising a receiver location and receiver frequency shift; wherein said 2D channel state comprises information pertaining to relative locations, frequency shifts, and reflector coefficients of reflection of said at least one transmitters, receivers, and reflectors; said method comprising: using said at least one transmitter and at least one processor to transmit direct OTFS pilot bursts, said direct OTFS pilot bursts comprising a plurality of OTFS pilot symbols Ppt,pf transmitted as OTFS pilot symbol waveform bursts Ppt,pf. Wp(pt, pf), over a plurality of combinations of times pt and frequencies pf, where each said pt and pf are unique pilot time-frequency coordinates chosen from a two dimensional pilot OTFS time-frequency grid, and all said OTFS pilot symbol waveform bursts Ppt,pf. Wp(pt, pf) are mutually orthogonal waveform bursts derived from time and frequency shifted versions of a same OTFS pilot basis waveform Wp; said receiver configured to receive at least said pilot bursts according to at least a two dimensional pilot OTFS time-frequency bin structure with bin sizes and bin-coordinate positions proportional to said OTFS time-frequency grid; wherein upon propagation through said impaired data channel, said direct OTFS pilot bursts then travel over at least one path, said at least one path comprising at least one of: a: direct OTFS pilot bursts traveling directly from said at least one transmitter to said at least one receiver; and b: replica OTFS pilot bursts comprising direct OTFS pilot bursts that have reflected off of said at least one reflector before reaching said at least one receiver, thereby producing direct OTFS waveform bursts that are further reflector time-delayed and reflector frequency-shifted at said at least one receiver; wherein at said at least one receiver, a resulting combination of any said transmitter frequency shifted and receiver frequency shifted direct OTFS pilot bursts and any said replica OTFS pilot bursts produces channel-convoluted OTFS pilot bursts; at said at least one receiver, using said bin structure to receive said channel-convoluted OTFS pilot bursts and using at least one processor to determine said 2D channel state of said impaired data channel connecting said at least one transmitter and said at least one receiver. |
