Hey, I did in fact save that info, forgot about it. To synopsize:
the patent no. is 5,400,322. March 21 1995. The abstract:
Allocations of bits per transmission symbol to subchannels in a transmission
system using multicarrier modulation are updated in response to requests
from a receiver to a transmitter of the system, each request identifying a
carrier whose bit allocation can be increased and a carrier whose bit
allocation can be decreased, so that the total number of bits per symbol can
be increased, decreased, or be unchanged. In order to synchronize bit
allocation changes, a transmitted symbol counter at the transmitter and a
received symbol counter at the receiver maintain synchronized symbol counts.
In response to a request for a change in bit allocations, the transmitter
sends a future symbol count value to the receiver, and the transmitter and
the receiver implement the change when their respective counters match this
count value.
Other References
Bingham, J., "Multicarrier Modulation for Data Transmission: An Idea
Whose Time Has Come," IEEE Communications Magazine, vol. 28, No. 5, pp.
5-14 (May 1990).
Fleming, S. et al., ADSL: "The On-Ramp to the Information Highway",
Telephony, pp. 20-26 (Jul. 12, 1993).
Hope this helps. Wendy |
