Wireless mesh network
Among other things, aspects, features, and implementations of wireless mesh networks and wireless mesh network devices are described.
1. A method comprising
receiving a signal at a node of an orthogonal frequency-division multiplexing wireless communication network from another node of the wireless communication network, the received signal including a desired signal component and a self-interference signal component,
performing a joint channel estimation process on a self-interference signal channel in a time domain and a desired signal channel in a frequency domain, the desired signal channel being associated with the desired signal component, the self-interference signal channel and the desired signal channel having respective frame timings that are not aligned, and
applying a cancellation process to the received signal based on the estimated self-interference signal channel.
2. The method of claim 1 in which the desired signal component comprises a known Demodulation Reference Signal (DM-RS).
3. The method of claim 1 in which the node comprises a node of a mesh network.
4. The method of claim 1 in which a frame offset between the frame timing of the self-interference signal channel and the frame timing of the desired signal channel is larger than the length of a cyclic prefix.
5. The method of claim 1 comprising representing the self-interference signal that is in the frequency domain and that is a component of the received signal in the frequency domain, as a function of known self-interference symbols in the time domain.
6. The method of claim 1 comprising computing the self-interference signal in the frequency domain including applying a time-domain-to-frequency-domain transform to the self-interference signal in the time domain.
7. The method of claim 1 in which the joint estimating comprises combining as a first matrix the known desired signal in the frequency domain and the known transform of the time domain self-interference signal into the frequency domain, combining as a second matrix the unknown desired signal channel in the frequency domain and the unknown self-interference channel in the time domain, and multiplying the first matrix by the second matrix.
8. The method of claim 1 in which the cancellation process comprises subtracting from the received signal in the time domain, the estimate of the self-interference channel in the time domain as applied to the self-interference signal component in the time domain, or by subtracting from the received signal in the frequency-domain, the estimate of the self-interference channel in the frequency domain as applied to the self-interference signal component in the time domain transformed to the frequency domain.
9. The method of claim 1 in which the joint channel estimation comprises a computation based on a QR decomposition of a matrix that combines a matrix of desired signal symbols and a matrix of self-interference symbols.
10. The method of claim 1 comprising reducing a length of an impulse response applicable to the joint channel estimation process.
11. The method of claim 1 in which the desired signal and the self-interference signal are up-sampled in the time domain before transmission and the joint channel estimation comprises down-sampling the self-interference signal in the time domain in accordance with corresponding down-sampling done on the received signal.
12. The method of claim 11 in which the self-interference channel occupies a narrower frequency band than the desired signal channel to an extent that the joint estimation process does not yield only a single solution, and the joint estimation process comprises estimating the self-interference channel using time domain samples of the self-interference signal at a sampling rate that is lower than a sampling rate applied to the received signal in the time domain, and estimating the self-interference channel based on fewer subcarriers.
13. The method of claim 1 in which the self-interference channel occupies a narrower frequency band than the desired signal channel to an extent that the joint estimation process does not yield only a single solution, and the joint estimation process comprises altering the signals of one or more of the subcarriers of the self-interference signal.
14. The method of claim 13 in which altering the signals of one or more of the subcarriers comprises transmitting a low level dither signal in one or more of the subcarriers.
15. The method of claim 1 in which two or more panels are transmitting, there are two or more corresponding self-interference signals, the received signal is received through a third panel, the desired signal comprises known reference symbols, and the joint channel estimation process comprises using the known reference symbols.
16. The method of claim 1 in which, when a level of the self-interference signal is greater than a threshold for a beam pair through which the received signal is received, the energy per resource element in a transmitting panel is reduced.
17. The method of claim 1 comprising measuring identifying beam pairs associated with self-interference signal levels higher than a threshold, and when two or more of such beam pairs are associated with sidelobes of a transmit or receive beam, adjusting the sidelobes to reduce the self-interference signal levels.
18. The method of claim 1 comprising, when a beam pair is associated with self-interference signal levels higher than a threshold, initiating half-duplex operation with dynamic time division multiplexing.
19. The method of claim 18 comprising, depending on the effect of the dynamic time division multiplexing, negotiating semi-static time division multiplexing.
20. A method comprising
receiving a signal at a node of an orthogonal frequency-division multiplexing wireless communication network from another node of the wireless communication network, the received signal including a desired signal component and a self-interference signal component, the desired signal being subject to phase jitter and the self-interference signal being subject to phase jitter, and
performing a joint phase jitter estimation process on a self-interference signal channel in a time domain and a desired signal channel in a frequency domain, the desired signal channel being associated with the self-interference signal component and the desired signal component, the self-interference signal channel and the desired signal channel having respective frame timings that are not aligned.