Multi-carrier communication systems employing variable symbol rates and number of carriers

摘要

A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of earners used. The selection of symbol rate and number of earners can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support. The receiver can determine the correct symbol rate and number of earners through a priori knowledge, a first exchange of packets in a base mode that all nodes can understand, or an indication in the header of the data packet which is transmitted in a base mode of operation that all nodes can understand.

主权项

1. A method of communicating from a first transceiver in a wireless multicarrier system comprising the steps of:
transmitting from the first transceiver a group of symbols using a first particular number of carriers and a first particular symbol rate during a first period of time; and transmitting from the first transceiver another group of symbols using a second particular number of carriers and a second particular symbol rate during a subsequent period of time, wherein at least one of the second particular number of carriers and the second particular symbol rate is different than the first particular number of carriers and the first particular symbol rate;wherein the second particular number of carriers and the second particular symbol rate are identified in a header portion of the group of symbols transmitted at the first particular number of carriers and the first particular symbol rate; and
further including the step of configuring the first transceiver to transmit the another group of symbols using the second particular number of carriers and the second particular symbol rate identified in the header portion of the group of symbols transmitted at the first particular number of carriers and the first particular symbol rate.