System for multi-frame alignment
View Patent ↗A bidirectional communication system is provided. In one embodiment, a system comprises a host; and a plurality of remote units, wherein a plurality of tones is shared among the plurality of remote units in order to communicate with the host using orthogonal frequency division multiplexing, wherein the plurality of tones is shared in a manner that permits at least two of the remote units to transmit to the host at any one time using the plurality of tones. The host causes at least one remote unit to adjust a timing of symbols transmitted on at least one of the plurality of orthogonal tones in order to improve an alignment of multiframes received at the host.
1. A system comprising:
a host; and
a plurality of remote units, wherein a plurality of tones is shared among the plurality of remote units in order to communicate with the host using orthogonal frequency division multiplexing, wherein the plurality of tones is shared in a manner that permits at least two of the remote units to transmit to the host at any one time using the plurality of tones; and
wherein the host causes at least one remote unit to adjust a timing of symbols transmitted on at least one of the plurality of orthogonal tones in order to improve an alignment of multiframes received at the host;
wherein the host:
determines a phase shift associated with the receipt at the host of a first symbol transmitted from one of the plurality of remote units; and
causes the at least one remote unit to add a delay to the transmission of a second symbol therefrom, wherein the delay is related to the phase shift.
2. The system of claim 1 , wherein the host causes the at least one remote unit to adjust the timing of symbols transmitted on the at least one of the plurality of tones in order to align symbols of a first frame of the multiframes when received at the host.
3. The system of claim 1 , wherein the host generates information indicative of a transmission adjustment for the at least one remote unit and communicates the information to the at least one remote unit for use by the at least one remote unit in making the transmission adjustment based at least in part on the information in order to improve the alignment of the multiframes when received at the host.
4. The system of claim 1 , wherein the host generates information indicative of a transmission adjustment for the at least one remote unit and communicates the information to the at least one remote unit; and
wherein the at least one remote unit adjusts a phase of a superframe clock signal based on the information.
5. The system of claim 1 , wherein the host communicates a command to the at least one remote unit, wherein the at least one remote unit adjusts the timing of symbols transmitted therefrom in response to the command.
6. The system of claim 1 , wherein the host causes the at least one remote unit to adjust at least one of a carrier amplitude and a carrier frequency.
7. The system of claim 1 , wherein the system is used in a wireless network.