Multi-carrier connection initialization and symbol transmission
View Patent ↗A method of transmitting symbols in a wireline multi-carrier communication system in which each symbol is modulated for transmission over a carrier group of pre-determined size. The method involves, identifying all available carrier groups, and transmitting a replicate of the symbol on each of the available carrier groups. In preferred embodiments, the individual signals transmitted over respective carriers are phase-offset relative to each other in order to mitigate potential peaks in signal power. Corresponding apparatus and the generated signal are also provided.
1. A method of transmitting symbols in a wireline multi-carrier communication system in which each symbol is modulated for transmission over a carrier group of known size, the method comprising the steps of:
identifying all available carrier groups; and
transmitting a replicate of the symbol on each of at least half of the available carrier groups.
2. A method according to claim 1 wherein the replicate of the symbol is transmitted on each of all available carrier groups.
3. A method according to claim 2 wherein each replicate of the symbol transmitted on each of all available carrier groups is phase-shifted relative to another replicate.
4. A method according to claim 1 additionally comprising the step of:
applying a phase-shift to each of said at least half one of the available carrier groups, whereby to mitigate peaks in transmitted instantaneous signal power across said at least half of the available carrier groups.
5. A method according to claim 1 additionally comprising the step of:
for at least one of said at least half of available carrier groups, phase-shifting a symbol portion transmitted on a first carrier in the carrier group relative to a second carrier in the carrier group, whereby to mitigate peaks in transmitted signal power across said at least half of the available carrier groups.
6. A method according to claim 5 , wherein each symbols portion within a carrier group is phase-shifted relative to other symbol portions of said carrier group.
7. A method according to claim 5 , wherein the step of phase-shifting is applied to all of said at least half of the available carrier groups.
8. A method of transmitting initialisation messages in a wireline multi-carrier communication system, the method comprising the steps of:
partitioning an initialisation message into one or more symbols;
modulating one of the symbols for transmission over a carrier group of known size;
identifying all available carrier groups; and
transmitting a replicate of said one of the symbols on each available carrier group.
9. A method according to claim 8 , wherein the initialisation messages are Digital Subscriber Line (DSL) messages.
10. A method according to claim 8 wherein the initialisation messages are selected from the group consisting of Very High Speed Digital Subscriber Line (VDSL) and Asymmetric Digital Subscriber Line (ADSL).
11. A transmitter for a wireline multi-carrier communication system comprising:
a modulator for modulating symbols for transmission over a pre-determined number of carriers;
a carrier allocater arranged to identify all available carrier groups having the pre-determined number of carriers; and
a replicator arranged to output a replicate of each of the symbols on each of the available carrier groups.
12. A modem comprising the transmitter according to claim 11 .
13. A transmitter according to claim 11 wherein the replicator is arranged to determine the transmission phase on available carrier responsive to pre-determined carrier phase-shift data.
14. A program for a computer on a machine readable medium for transmitting symbols in a wireline multi-carrier communication system in which each symbol is modulated for transmission over a carrier group of known size, the program being arranged to perform the steps of:
identifying all available carrier groups; and
transmitting a replicate of the symbol on each of at least half of the available carrier groups.
15. A program for a computer on a machine readable medium for transmitting initialisation messages in a wireline multi-carrier communication system, the program being arranged to perform the steps of:
partitioning an initialisation message into one or more symbols;
modulating one of the symbols for transmission over a carrier group of known size;
identifying all available carrier groups; and
transmitting a replicate of said one of the symbols on each available carrier group.
16. A method of establishing a connection between a transmitter and a receiver in a wireline communication system, the method comprising the steps of:
at the transmitter, partitioning a connection initialisation message into one or more symbols, modulating each symbol for transmission over a carrier group of pre-determined size, identifying all available carrier groups, and transmitting a replicate of each symbol on at least half the available carrier groups; and the receiver, receiving said replicates of each symbol, reconstructing the initialisation message from said received replicate symbols, and opening the connection in response to the initialisation message.