User-focusing technique for wireless communication systems
View Patent ↗Systems and methods for wireless communication in a system including a transmitter, a receiver, and a plurality of propagation paths formed between the transmitter and the receiver which are capable of carrying a signal transmitted by the transmitter to the receiver. The method includes transmitting a first signal from the transmitter to the receiver via a propagation path of the plurality of propagation paths, receiving the first signal at the receiver, performing a channel estimation of the first signal to obtain path parameter information of the propagation path, sending the channel estimation from the receiver to the transmitter via the propagation path, predistorting a second signal at the transmitter according to the channel estimation, transmitting the predistorted signal from the transmitter to the receiver via the propagation path, and receiving the predistorted signal at the receiver.
1. A method for wireless communication in a system including a transmitter, a receiver, and a plurality of propagation paths formed between the transmitter and the receiver which are capable of carrying a signal transmitted by the transmitter to the receiver, the method comprising:
transmitting a first signal from the transmitter to the receiver via a first propagation path of the plurality of propagation paths;
receiving the first signal at the receiver;
performing a channel estimation based on the first signal to obtain path parameter information of the first propagation path;
sending the channel estimation that includes the path parameter information from the receiver to the transmitter via the first propagation path;
predistorting a second signal at the transmitter in a time domain, a frequency domain, and a spatial domain, according to the channel estimation based on the first signal;
transmitting the predistorted second signal from the transmitter to the receiver via the first propagation path; and
receiving the predistorted second signal at the receiver.
2. The method of claim 1 , wherein the path parameter information of the first propagation path includes at least one of an estimation of a delay, an estimation of a Doppler frequency, an estimation of a direction of arrival, an estimation of a direction of departure, and an estimation of a complex amplitude of the first propagation path.
3. The method of claim 2 , wherein the path parameter information of the first propagation path further includes an estimation of a polarization status of the first propagation path.
4. The method of claim 1 , wherein the path parameter information is obtained by at least one estimation technique of the group consisting of a maximum-likelihood estimation algorithm, periodogram, correlatorgram, spectral-based methods, Bartlett beamformers, Capon beamformers, subspace-based techniques, MUSIC (MUltiple SIgnal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), approximation of the maximum-likelihood method based on iterative schemes, SAGE (Space-Alternating Generalized Expectation-maximization), RiMAX (Richter's Maximum Likelihood method), maximum-a-posteriori based methods, Evidence Framework, Bayesian techniques, tracking algorithms, Kalman filtering techniques, enhanced Kalman filtering techniques, particle filtering techniques, and least-square-error methods.
5. The method of claim 1 , the method further comprising:
performing a system response estimation of the first signal to obtain parameter information of the system;
sending the system response estimation from the receiver to the transmitter via the first propagation path; and
further predistorting the predistorted second signal at the transmitter according to the system response estimation.
6. The method of claim 1 , further comprisingequalizing the predistorted second signal at the receiver.
7. The method of claim 6 , wherein equalizing the predistorted second signal is performed using a joint processing technique in a coordinated multiple-point (CoMP) system.
8. A system for wireless communication comprising:
a receiver;
a transmitter; and
a plurality of propagation paths formed between the transmitter and the receiver which are capable of carrying a signal transmitted by the transmitter to the receiver,
wherein the receiver is configured to receive a first signal that is transmitted along a first propagation path of the plurality of propagation paths from the transmitter, perform a channel estimation based on the first signal to obtain path parameter information of the first propagation path, and send the channel estimation that includes the path parameter information to the transmitter via the first propagation path, and
wherein the transmitter is configured to predistort a second signal in a time domain, a frequency domain, and a spatial domain according to the channel estimation that is based on the first signal and received from the receiver and to transmit the predistorted second signal to the receiver via the first propagation path.
9. The system of claim 8 , wherein the path parameter information of the first propagation path includes at least one of an estimation of a delay, an estimation of a Doppler frequency, an estimation of a direction of arrival, an estimation of a direction of departure, and an estimation of a complex amplitude of the first propagation path.
10. The system of claim 8 , wherein the path parameter information of the first propagation path further includes an estimation of a polarization status of the first propagation path.
11. The system of claim 8 , wherein the path parameter information is obtained by at least one estimation technique of the group consisting of a maximum likelihood estimation algorithm, periodogram, correlatorgram, spectral-based methods, Bartlett beamformers, Capon beamformers, subspace-based techniques, MUSIC (MUltiple SIgnal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), approximation of the maximum-likelihood method based on iterative schemes, SAGE (Space-Alternating Generalized Expectation-maximization), RiMAX (Richter's Maximum Likelihood method), maximum-a-posteriori based methods, Evidence Framework, Bayesian techniques, tracking algorithms, Kalman filtering techniques, enhanced Kalman filtering techniques, particle filtering techniques, and least-square-error methods.
12. The system of claim 8 , wherein the transmitter and the receiver each comprise multiple antennas in a multiple-input and multiple-output (MIMO) wireless communication system or a single antenna in a single-input and single-output (SISO) wireless communication system.
13. The system of claim 8 , wherein the receiver is further configured to perform a system response estimation of the first signal to obtain parameter information of the system and to send the system response estimation from the receiver to the transmitter via the first propagation path,
wherein the transmitter is further configured to further predistort the predistorted second signal according to the system response estimation.
14. The system of claim 8 , wherein the receiver is further configured to equalize the predistorted second signal.
15. A base station for performing wireless communication with a receiver in a wireless device via a plurality of propagation paths, the base station comprising:
a transmitter;
a computing device; and
a computer-readable storage medium having computer-executable instructions stored thereon that are executable by the computing device to perform operations comprising:
transmitting a first signal from the transmitter to the receiver via a first propagation path of the plurality of propagation paths;
receiving a channel estimation based on the first signal, the channel estimation including path parameter information of the first propagation path;
predistorting a second signal in a time domain, a frequency domain, and a spatial domain according to the channel estimation based on the first signal; and
transmitting the predistorted second signal from the transmitter to the receiver via the first propagation path.
16. The base station of claim 15 , wherein the path parameter information of the first propagation path includes at least one of an estimation of a delay, an estimation of a Doppler frequency, an estimation of a direction of arrival, an estimation of a direction of departure, an estimation of a complex amplitude of the first propagation path, and an estimation of a polarization status of the first propagation path.
17. The base station of claim 15 , wherein the transmitter comprises multiple antennas in a multiple-input and multiple-output (MIMO) wireless communication system or a single antenna in a single-input and single-output (SISO) wireless communication system.
18. The base station of claim 15 , wherein the computing device performs further operations comprising:
receiving a system response estimation of the first signal that contains parameter information of the base station, the wireless device, and of the first propagation path; and
further predistorting the predistorted second signal according to the system response estimation.
19. A wireless device for performing wireless communication with a base station with a transmitter via a plurality of propagation paths, the wireless device comprising:
a receiver;
a computing device; and
a computer-readable storage medium having computer-executable instructions stored thereon that are executable by the computing device to perform operations comprising:
receiving a first signal at the receiver via a first propagation path of the plurality of propagation paths;
performing a channel estimation based on the first signal to obtain path parameter information of the first propagation path;
sending the channel estimation that includes the path parameter information to the transmitter; and
receiving a second signal via the first propagation path, the second signal predistorted in a time domain, a frequency domain, and a spatial domain according to the channel estimation based on the first signal.
20. The wireless device of claim 19 , wherein the path parameter information of the first propagation path includes at least one of an estimation of a delay, an estimation of a Doppler frequency, an estimation of a direction of arrival, an estimation of a direction of departure, and an estimation of a complex amplitude of the first propagation path.
21. The wireless device of claim 20 , wherein the path parameter information of the first propagation path further includes an estimation of a polarization status of the first propagation path.
22. The wireless device of claim 19 , wherein the path parameter information is obtained by at least one estimation technique of the group consisting of a maximum likelihood estimation algorithm, periodogram, correlatorgram, spectral-based methods, Bartlett beamformers, Capon beamformers, subspace-based techniques, MUSIC (MUltiple SIgnal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), approximation of the maximum-likelihood method based on iterative schemes, SAGE (Space-Alternating Generalized Expectation-maximization), RiMAX (Richter's Maximum Likelihood method), maximum-a-posteriori based methods, Evidence Framework, Bayesian techniques, tracking algorithms, Kalman filtering techniques, enhanced Kalman filtering techniques, particle filtering techniques, and least-square-error methods.
23. The wireless device of claim 19 , wherein the receiver comprises multiple antennas in a multiple-input and multiple-output (MIMO) wireless communication system or a single antenna in a single-input and single-output (SISO) wireless communication system.
24. The wireless device of claim 19 , wherein the computing device performs further operations comprising:
receiving a third signal along another of the plurality of propagation paths, the third signal being phase aligned with the second signal when received by the receiver such that no equalization of the second and third signals is performed by the wireless device.
25. The wireless device of claim 19 , wherein the computing device performs further operations comprising:
generating a system response estimation of the first signal that contains parameter information of the base station, the wireless device, and of the first propagation path; and
receiving the second signal predistorted based on the system response estimation.