Synchronization of adaptive filter switching and channel equalization in full duplex (fdx) cable modems
AssigneeIntel Corporation
InventorsNathan Goichberg, Shaul Shulman, Thushara Hewavithana
Life of this patent
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Abstract
Synchronizing methods and architectures for cable modems to transmit and receive Full Duplex (FDX) resource block allocations (RBAs) using filter switching and coordinated updating of equalization coefficients. A cable modem including a block of switchable filters, an analog front end (AFE) and a PHY/MAC System on a Chip (SoC) tuner to, at least in part, provide signals to switch the switchable filters in accordance with the RBA changes and synchronize updating tuner equalizations to match filter switching in a coordinated manner by marking received data at the AFE.
Claims21
In a cable modem having an analog front end (AFE), a physical layer modulator (PHY) and a medium access control circuitry (MAC), that operates in full duplex (FDX) mode, and having a switchable filter block and variable equalizer coefficients in the PHY, a processor configured to:
- receive a command at the MAC from the cable modem, wherein the received command comprises a resource block allocation (RBA) change from a cable modem termination system (CMTS), wherein the RBA change comprises altering a first allocation of downstream and upstream transmission channels to a second, different allocation of downstream and upstream transmission channels, wherein altering the allocation comprises changing a channel from a downstream transmission direction to an upstream transmission direction, or vice-versa;
- and
- trigger the MAC to send a filter switch control signal to the analog front end based on the received command to:
- cause the AFE, in response to the filter switch control signal, to switch a filter path and insert a filter switching mark in one or more samples received;
- and
- cause the PHY to change its variable equalizer coefficients to reflect current calibration data for the switched filter path in substantial synchronization with receiving samples including the filter switching mark from the AFE.
(canceled)
A communication system comprising:
- a block of switchable filters to receive and transmit full duplex (FDX) signals according to a network provided resource block allocation (RBA) protocol;
- and
- a tuner system in communication with the block of switchable filters, including physical layer (PHY) and medium access control (MAC) functionality, said MAC functionality including signaling to cause the block of switchable filters to change a filter path corresponding to a change in RBA and to mark received samples when the filter path changes, and the PHY synchronizing equalizer coefficient changes to compensate for the changed filter path based on the marked samples.
- wherein the RBA change due to the signaling comprises altering a first allocation of downstream and upstream transmission channels to a second, different allocation of downstream and upstream transmission channels, wherein altering the allocation comprises changing a channel from a downstream transmission direction to an upstream transmission direction, or vice-versa.
A method of synchronizing filter switching and updating channel equalization coefficients in a cable modem having a switchable filter block, an analog front end (AFE), and a digital tuner including physical layer (PHY) and medium access control (MAC) functionality, the method comprising:
- receiving a command at the cable modem from a cable modem termination system (CMTS);
- and
- sending a filter switch control signal to the AFE from the MAC based on the received command to;
- cause the AFE, in response to the filter switch control signal, to switch a filter path in the switchable filter block, and insert a filter switching mark in one or more samples received;
- and
- cause the PHY to change its equalizer coefficients to compensate for the switched filter path in substantial synchronization with receiving samples including the filter switching mark from the AFE.
- wherein the received command comprises a resource block allocation (RBA) change from the cable modem termination system (CMTS), and wherein the RBA change comprises altering a first allocation of downstream and upstream transmission channels to a second, different allocation of downstream and upstream transmission channels, wherein altering the allocation comprises changing a channel from a downstream transmission direction to an upstream transmission direction, or vice-versa.
(canceled)
Dependencies are inferred from the claim text.