Method of synchronizing a communication system
View Patent ↗A method of synchronizing a time division duplex (TDD) multi-line, multi-carrier data communication system is provided. Synchronization is established using unique pseudo-random bit sequences (PRBS) from a common generator polynomial having different seed values. Due to low correlation of PRBS generated with different seed values, a remote unit can only synchronize to its intended signal effectively mitigating far-end and near-end crosstalk impact of large bandwidth very high speed digital subscriber lines (VDSL).
1. A method for synchronizing communication signals, the method comprising:
generating n unique seed values for n remote units;
assigning, for the n remote units, a corresponding one of the n unique seed values to a corresponding one of the n remote units;
transmitting from a central unit to the n remote units the corresponding assigned one of the n unique seed values;
constructing unique pseudo-random bit sequences for each of the n remote units using the corresponding assigned one of the n unique seed values and at least one pseudo-random bit sequence generator polynomial; and
transmitting the unique pseudo-random bit sequences to corresponding n remote units for the synchronization of the communication signals.
2. The method according to claim 1 further comprising assigning the n unique seed values in unique seed value pairs.
3. The method according to claim 2 , wherein the assigned unique seed value pairs include a first unique seed value to construct the unique pseudo-random bit sequences for downstream communication signals and a second unique seed value to construct the unique pseudo-random bit sequences for upstream communication signals.
4. The method according to claim 2 , wherein the assigned unique seed value pairs are transmitted to their corresponding n remote units prior to the synchronization.
5. The method according to claim 2 , wherein the assigned unique seed value pairs are transmitted to their respective n remote units using a low-bandwidth handshaking or message-exchange protocol.
6. The method according to claim 1 , wherein the n unique seed values are assigned by an independent protocol.
7. The method according to claim 6 , wherein the independent protocol comprises G.994.1.
8. The method according to claim 1 , wherein the communication signals utilize any of: G.fast, Omega DSL or VDSL standards.
9. The method according to claim 1 , wherein the communication signals are transmitted across a multi-line, multi-carrier communication system.
10. The method according to claim 9 , wherein the communication system comprises a multi-line time-division duplex (TDD), multi-carrier VDSL communication system.
11. A system for synchronizing communication signals comprising:
a pseudo-random bit sequence generator configured to generate a pseudo-random bit sequence;
a seed value generator configured to generate for each of a plurality of remote communication units at least one unique seed value corresponding to each of the plurality of remote communication units, the at least one unique seed value seeding the generated pseudo-random bit sequence to create a plurality of unique seed pseudo-random bit sequences; and
a transmitter configured to transmit the generated unique seed values to the corresponding one of the plurality of remote units and further configured to transmit the unique pseudo-random bit sequences to their corresponding remote communication units for synchronization of communication signals.
12. The system according to claim 11 , wherein the transmitter is further configured to transmit across multiple lines using time-division duplex (TDD).
13. The system according to claim 11 , wherein the seed value generator is further configured to generate, for each of the plurality of remote communication units, a pair of unique seed values.
14. The system according to claim 13 , wherein the pair of unique seed values includes a first unique seed value for downstream communications synchronization and a second unique seed value for upstream communications synchronization.
15. The system according to claim 13 , wherein the transmitter is further configured to transmit the pair of unique seed values to a corresponding remote communication unit.
16. The system according to claim 15 , wherein the transmitter is further configured to transmit the pair of unique seed values using a low-bandwidth handshaking or message-exchange protocol.
17. The system according to claim 11 , wherein the communication signals utilize at least one of: G.fast, Omega DSL or VDSL standards.
18. A method for synchronizing downstream and upstream communication signals between a central unit and a plurality of remote units, the method comprising:
generating unique seed value pairs corresponding to each of the plurality of remote units;
assigning, for the plurality of remote units, a corresponding one of the unique seed value pairs to a corresponding one of the plurality of remote units;
constructing, for each of the plurality of remote units, a downstream pseudo-random bit synchronizing signal including a first seed of the corresponding unique seed value pairs and a pseudo-random bit sequence generator polynomial;
constructing, for each of the plurality of remote units, an upstream pseudo-random bit synchronizing signal using a second seed of the corresponding unique seed value pairs and the pseudo-random bit sequence generator polynomial; and
transmitting the downstream and upstream pseudo-random bit synchronizing signals for synchronization of the downstream and upstream communication signals.
19. The method according to claim 18 further comprising transmitting the unique seed value pairs to a corresponding one of the plurality of remote units before synchronization.
20. The method according to claim 18 further comprising transmitting the downstream and upstream pseudo-random bit synchronizing signals during allocated time slots for continued synchronization of the downstream and upstream communication signals.