Methods and Apparatus for Fast Downlink Information of Uplink Out-of-Synchronization

A communication node adapted to transmit and receive electromagnetic signals, comprising:

• a detector adapted to determine whether a first received link is synchronized;
• and
• a device, responsive to the detector, adapted to include an out-of-synchronization (OoS) signal in signals transmitted on a second link, the OoS signal indicating that the first received link is synchronized or OoS, wherein the OoS signal comprises:
• a change-of-sign of at least one symbol transmitted on the second link, or
• a power level offset between information elements included in a signal sent on the second link.

A communication terminal adapted to transmit and receive electromagnetic signals, comprising:

• a device adapted to recover information, including pilot symbols and transmit power control (TPC) commands, from electromagnetic signals received on a first link;
• a control unit adapted to control a power level of electromagnetic signals transmitted by the terminal on a second link based on the TPC commands;
• and
• a detector adapted to monitor recovered information for an out of synchronization (OoS) signal in signals received on the first link, the OoS signal indicating that the second link is synchronized or OoS, wherein the OoS signal comprises:
• a change-of-sign of at least one symbol transmitted on the second link, or
• a power level offset between information elements included in a signal sent on the second link.

A communication system, comprising:

• at least one base station adapted to propagate and receive electromagnetic signals, wherein the electromagnetic signals include at least one common pilot channel (CPICH) and at least one dedicated physical channel (DPCH);
• and
• at least one user equipment adapted to propagate to and receive electromagnetic signals from the at least one base station, wherein the user equipment includes:
• a device adapted to recover information from the CPICH and the DPCH, including pilot symbols and transmit power control (TPC) commands;
• and
• a control unit adapted to control a power level of a transmitter in the user equipment based on the TPC commands;
• wherein the base station includes a detector adapted to determine whether an uplink (UL) from the user equipment is synchronized;
• and when the detector determines the UL is out of synchronization (OoS), the base station alters the DPCH pilot symbols propagated to the user equipment.

A method of indicating that a first link to a communication node is out of synchronization (OoS), comprising the steps of:

• checking, by the node, whether the first link is OoS;
• if the first link is synchronized, transmitting pilot symbols having a first scale factor on a second link;
• and
• if the first link is OoS, transmitting pilot symbols having a second scale factor on the second link.

A method of controlling transmit power on a first link to a communication node, comprising the steps of:

• detecting a scale factor of pilot symbols received on a second link;
• wherein if the first link is synchronized, pilot symbols having a first scale factor are detected, and if the first link is out of synchronization (OoS), pilot symbols having a second scale factor are detected;
• if pilot symbols having the second scale factor are detected, limiting transmit power control (TPC) commands received on the second link in a TPC command combination;
• and
• if pilot symbols having the first scale factor are detected, including TPC commands received on the second link in the TPC command combination.

A method in a user equipment of determining that an uplink (UL) to a communication node is out of synchronization (OoS), comprising the steps of:

• comparing newer transmit power control (TPC) commands to older TPC commands received from the node;
• if an output signal generated from the comparing step exceeds a threshold, measuring a signal-to-interference ratio (SIR) for a downlink (DL) from the node;
• and
• determining, based on the measured SIR, whether the node is following TPC commands sent to the node in the UL;
• wherein if the node is not following the TPC commands, OoS is determined.