Channel simulator using path loss of terminal transmit power to establish attenuation amount in uplink signal to base station
Provided is a control method for a channel simulator, capable of expanding a processable dynamic range of an uplink signal receiving unit while adopting an A/D converter (ADC) having low resolution by adjusting an attenuation amount of the uplink signal receiving unit in a large-capacity channel simulator having P base stations and Q terminal interfaces. In a control method for a channel simulator that includes P base station interface cards (BS I/F cards) (P>2; P is an integer), a link processor block, and Q user equipment interface cards (UE I/F cards) (Q>2; Q is an integer) to form channels with respect to all paths between P base stations and Q terminals, the control method for the channel simulator according to the present invention includes: (a) establishing a table representing an attenuation amount offset in an uplink signal receiving unit of the UE I/F card over a path loss based on log data with respect to terminal transmission power over the path loss for eliminating change of the path loss exerting an influence upon the terminal transmission power; (b) searching for a specified path loss value from the table established in step (a) to determine an attenuation amount corresponding to the specified path loss value when a path loss value with respect to an uplink signal processing process is specified; and (c) adjusting an attenuation amount in the uplink signal receiving unit of the UE I/F card based on the attenuation amount determined in step (b).
1. A control method for a channel simulator that includes P base station interface cards (BS I/F cards), wherein P is an integer greater than 2, a link processor block, and Q user equipment interface cards (UE I/F cards), wherein Q is an integer greater than 2 to form channels with respect to all paths between P base stations and Q terminals, the control method comprising:
(a) establishing a table representing an attenuation amount offset in an uplink signal receiving unit of the UE I/F card over a path loss based on log data with respect to terminal transmission power over the path loss for eliminating change of the path loss exerting an influence upon the terminal transmission power;
(b) searching for a specified path loss value from the table established in step (a) to determine an attenuation amount corresponding to the specified path loss value when a path loss value with respect to an uplink signal processing process is specified;
(c) adjusting an attenuation amount in the uplink signal receiving unit of the UE I/F card based on the attenuation amount determined in step (b); and
(d) restoring the path loss value, which is changed based on the attenuation amount adjusted in step (c), into an original value by adjusting an amplifier gain of the BS I/F card or a link processing block.
2. The control method of claim 1 , wherein an overall path loss range in the table is divided at equidistant intervals.
3. The control method of claim 1 , wherein an overall attenuation amount offset range in the table is divided at equidistant intervals.
4. A control method for a channel simulator that includes P base station interface cards (BS I/F cards), wherein P is an integer greater than 2, a link processor block, and Q user equipment interface cards (UE I/F cards), wherein Q is an integer greater than 2 to form channels with respect to all paths between P base stations and Q terminals, the control method comprising:
(a) establishing a table representing an attenuation amount offset in an uplink signal receiving unit of the UE I/F card over a path loss based on log data with respect to terminal transmission power over the path loss for eliminating change of the path loss exerting an influence upon the terminal transmission power;
(b) searching for a specified path loss value from the table established in step (a) to determine an attenuation amount corresponding to the specified path loss value when a path loss value with respect to an uplink signal processing process is specified; and
(c) adjusting an attenuation amount in the uplink signal receiving unit of the UE I/F card based on the attenuation amount determined in step (b),
wherein if an attenuation amount offset corresponding to the specified path loss value is not found in the table in step (b), interpolation is performed based on attenuation amount offsets for upper and lower path loss values of the specified path loss value to determine a corresponding attenuation amount.