Multiple rate architecture for wireline communication system
A discrete multitone (DMT) transceiver communicates with multiple channels generates and receives DMT symbols each having a duration of a timeslot. A transmitter portion of the transceiver includes a symbol processor which generates symbols for multiple channels sequentially, and stores the generated symbols in a buffer until they are transmitted. A receiver portion simultaneously receives symbols on multiple channels and stores the symbols in a buffer, from which the symbols on different channels are read and processed sequentially. To reduce the rate of communication on a given channel, the symbol processors may be idle in respect of some of the timeslots corresponding to that channel. The transceiver may alternatively be an OFDM transceiver.
1 . A transmitter that generates discrete multitone (DMT) or orthogonal frequency division multiplex (OFDM) symbols for transmission to multiple channels, the transmitter comprising:
a symbol processor operable to generate symbols for the multiple channels sequentially,
a buffer unit operable to store the generated symbols, and
a transmission unit operable to read symbols from the buffer unit and transmit the read symbols simultaneously on corresponding channels.
2 . The transmitter of claim 1 wherein the symbol processor comprises a plurality of processing units arranged in a pipeline, wherein each processing unit is operable to process data in different channels sequentially in respective sub-timeslots which are portions of a timeslot, and wherein at least two of the processing units are arranged during each sub-timeslot to process data in different channels.
3 . The transmitter of claim 2 wherein the transmission unit is operable to transmit data to each of the channels at an independently variable transmission rate.
4 . The transmitter of claim 3 wherein the variable transmission rate in each of the channels is variable by controlling the processing units of the symbol processor to be idle during selected sub-timeslots corresponding to the channel.
5 . The transmitter of claim 1 wherein the transmission unit is operable to transmit data to each of the channels in a selected one of a group of protocols comprising at least one ADSL protocol or at least one VDSL protocol.
6 . The transmitter of claim 1 wherein the buffer unit comprises a FIFO buffer for each channel, and wherein a timing of the generation of the symbols in each channel is controlled based on the values of pointers for a corresponding FIFO buffer.
7 . A receiver that receives discrete multitone (DMT) or orthogonal frequency division multiplex (OFDM) symbols from multiple channels, the receiver comprising:
a receiving unit operable to receive symbols simultaneously from respective channels and store the received symbols in a buffer unit, and
a symbol processor operable to read the symbols from the buffer sequentially, and process the read symbols sequentially.
8 . The receiver of claim 7 wherein the symbol processor comprises a plurality of processing units arranged in a pipeline, each processing unit operable to process data in different channels sequentially in respective sub-timeslots which are portions of a timeslot, and wherein at least two of the processing units are arranged during each sub-timeslot to process data in different channels.
9 . The receiver of claim 8 wherein the symbol processor is operable to process data received from each of the channels at an independently variable rate.
10 . The receiver of claim 9 wherein the processing rate in each of the channels is variable by controlling the processing units of symbol processor to be idle during selected sub-timeslots corresponding to the channel.
11 . The receiver of claim 6 wherein the receiver is operable to transmit data to each of the channels in a selected one of a group of protocols comprising at least one ADSL protocol or at least one VDSL protocol.
12 . The receiver of claim 7 wherein the buffer unit comprises a FIFO buffer for each channel, wherein a timing of processing of the symbols in each channel is controlled based on values of pointers for a corresponding FIFO buffer.
13 . A transmitter that generates discrete multitone (DMT) or orthogonal frequency division multiplex (OFDM) symbols for transmission to multiple channels, the transmitter comprising:
symbol processing means for generating symbols for multiple channels sequentially,
buffer means for storing the generated symbols, and
transmission means for reading symbols from the buffer unit and transmitting the read symbols simultaneously on the corresponding channels.
14 . The transmitter of claim 13 wherein the symbol processor means comprises a plurality of processing means arranged in a pipeline, wherein each processing means is operable to process data in different channels sequentially in respective sub-timeslots which are portions of a timeslot, and wherein at least two of the processing means are arranged during each sub-timeslot to process data in different channels.
15 . A receiver that receives discrete multitone (DMT) or orthogonal frequency division multiplex (OFDM) symbols from multiple channels, the receiver comprising:
receiving means for receiving symbols simultaneously from respective channels and store the received symbols in a buffer unit, and
symbol processor means for reading the symbols from the buffer sequentially, and process the read symbols sequentially.
16 . The receiver of claim 15 wherein the symbol processor means comprises a plurality of processing means arranged in a pipeline, wherein each processing means is operable to process data in different channels sequentially in respective sub-timeslots which are portions of a timeslot, and wherein at least two of the processing means are arranged during each sub-timeslot to process data in different channels.
17 . The receiver of claim 15 wherein the symbol processor means is operable to process data received from each of the channels at an independently variable rate.
18 . A method for generating DMT or OFDM symbols for transmission to multiple channels, the transmitter comprising:
generating symbols for multiple channels sequentially;
storing the generated symbols; and
reading symbols from the buffer unit and transmitting the read symbols simultaneously on corresponding channels.
19 . The method of claim 18 where transmitting the read symbols comprises transmitting data to each of the channels at an independently variable transmission rate.
20 . The method of claim 19 wherein transmitting data to each of the channels at an independently variable transmission rate comprises controlling the processing units of the symbol processor to be idle during selected sub-timeslots corresponding to the channel.