Antenna adaptation comparison method for high mobility
A system causes a scan angle of a directional antenna to change temporarily from a current scan angle to at least one trial scan angle during reception of predetermined portions of an information carrying signal. At the trial scan angle(s), a trial metric associated with each trial scan angle is determined by the system. The system then selects a next scan angle based on the trial metrics. Examples of predetermined portions of the information carrying signal include the Power Control Bit (PCB) and Forward Error Correction (FEC) block.
1 . A method for adapting a directional antenna by a wireless transmit/receive unit (WRTU) during a non-idle time comprising:
causing a scan angle of the antenna to change temporarily from a current scan angle to at least one trial scan angle during the reception of an information carrying signal;
determining a metric associated with each of the trial scan angles; and
selecting a next scan angle based on the trial metrics.
2 . The method of claim 1 , wherein said changing of the scan angle is conducted during reception of a Power Control Bit (PCB) to minimize the effect on the transfer of information in the information carrying signal.
3 . The method of claim 1 , wherein said changing of the scan angle is conducted during reception of a forward error correction (FEC) code block to minimize the effect on the transfer of information in the information carrying signal.
4 . The method of claim 1 , wherein said changing of the scan angle is conducted during reception of a pilot signal to minimize the effect on the transfer of information in the information carrying signal.
5 . The method according to claim 2 , wherein the dwell time of the Power Control Bit is less than the duration of a single power control command generation period.
6 . The method according to claim 2 , wherein the Power Control Bit (PCB) is during at least one of the following:
low information transfer;
receipt of one or more Forward Error Correction (FEC) bits in an FEC block;
a time when no traffic channel is assigned; or
a time when no payload is assigned.
7 . The method according to claim 1 , wherein the trial metrics are a function of at least one of the following:
parameters of a control channel;
parameters of an assigned traffic channel; or
parameters of any forward link channel.
8 . The method according to claim 1 , further including:
determining a current metric associated with a current scan angle of the antenna; and
selecting a next scan angle includes comparing a subset of trial metrics with the current metric.
9 . The method according to claim 1 , further including:
determining multiple trial metrics for the trial scan angles; and
selecting a next scan angle takes the multiple trial metrics into account.
10 . The method according to claim 7 , further including averaging or accumulating the multiple trial metrics.
11 . The method according to claim 1 , further including utilizing information from the forward link to determine the quality of the current scan angle for Time Division Duplex (TDD) systems.
12 . The method according to claim 1 , further including:
transmitting a signal at each trial scan angle and receiving a metric corresponding thereto from a base station; and
using the received metrics for selecting a next scan angle in a reverse path.
13 . The method according to claim 12 , used in a Frequency Division Duplex (FDD) or Time Division Duplex (TDD) system.
14 . The method according to claim 1 , used in a TDD system, wherein at each trial scan angle, the method further includes:
transmitting a signal to a base station; and
wherein determining a trial metric includes receiving the trial metric from the base station.
15 . The method according to claim 1 , further including determining a received channel parameter and changing a trial scan parameter based on the received channel parameter.
16 . A wireless transmit/receive unit (WRTU) in a wireless communication system for communicating with a base station, wherein said WRTU adapts a directional antenna during a non-idle time comprising:
a scanned controller to cause a scan angle of the antenna to change temporarily from a current scan angle to at least one trial scan angle during the reception of an information carrying signal;
a processor coupled to the scanned controller to determine a metric associated with each of the trial scanned angles; and
a selection unit coupled to the processor to select a next scan angle based on the trial metrics.
17 . The WRTU of claim 16 , wherein the scan angle is changed during reception of a Power Control Bit (PCB) to minimize the effect on the transfer of information in the information carrying signal.
18 . The method of claim 16 , wherein said scan angle is changed during reception of a Forward Error Correction (FEC) code block to minimize the effect on the transfer of information in the information carrying signal.
19 . The method of claim 16 , wherein the scan angle is changed during reception of a pilot signal to minimize the effect on the transfer of information in the information carrying signal.
20 . The WRTU according to claim 16 , wherein the dwell time of the Power Control Bit (PCB) is less than the duration of a single power control command generation period.
21 . The WRTU according to claim 16 , wherein the Power Control Bit (PCB) is during at least one of the following:
low information transfer;
receipt of one or more Forward Error Correction (FEC) bits in an FEC block;
a time when no traffic channel is assigned; or
a time when no payload is assigned.
22 . The WRTU according to claim 16 , wherein the metrics are a function of at least one of the following:
parameters of a control channel;
parameters of an assigned traffic channel; or
parameters of any forward link channel.
23 . The WRTU according to claim 16 , wherein the processor determines a current metric associated with a current scan angle of the directional antenna and the selection unit selects a next scan angle by comparing a subset of trial metrics with the current metric.
24 . The WRTU according to claim 16 , wherein the processor determines multiple trial metrics for the trial scan angles and the selection unit selects a next scan angle by taking the multiple trial metrics into account.
25 . The WRTU according to claim 24 , wherein the processor includes an arithmetic unit to average or accumulate the multiple trial metrics.
26 . The WRTU according to claim 16 , wherein the processor uses the selected scan angle to determine the quality of the scan angle for Time Division Duplex (TDD) systems.
27 . The WRTU according to claim 16 , further including:
a transceiver to transmit a signal at each trial angle and receive a metric corresponding thereto from a base station; and
wherein the processor coupled to the transceiver uses the received metrics for selecting a next scan angle in a reverse path.
28 . A WRTU according to claim 16 , used in a Frequency Division Duplex (FDD) or Time Division Duplex (TDD) system.
29 . The WRTU according to claim 16 , used in a TDD system, wherein at each trial scan angle, the processor transmits a signal to a base station and responsively receives the trial metric from the base station.
30 . The WRTU according to claim 16 , wherein the processor receives a channel parameter and changes a trial scan parameter based on the receiver channel parameter.