TH36174A - Methods and devices to reduce the effects of fading conditions in communication systems. - Google Patents

Abstract

DC60 (01/02/42) In a communication system (100) that transmits radio frequency signals from a transmitting source and receives them at a receiving unit, methods and devices have been disclosed to reduce the effects of fading conditions of the radio frequency signal at the receiving unit. These methods and devices include fading detection, radio frequency monitoring to detect power limiting conditions occurring at the transmitting source, and changes in antenna characteristics in the communication system when power limiting and fading conditions occur. During the monitoring phase, power limiting is detected at a threshold consisting of the cumulative number of power increase commands. In a communication system (100) that transmits radio frequency signals from a transmitting source and receives them at a receiving unit, methods and devices have been disclosed to reduce the effects of fading conditions of the radio frequency signal at the receiving unit. These methods and devices include fading detection, radio frequency monitoring to detect power limiting conditions occurring at the transmitting source, and changes in antenna characteristics in the communication system when power limiting and fading conditions occur. During the monitoring phase, power limiting is detected at a threshold consisting of the cumulative number of power increase commands. Changes that consist of the cumulative number of power-up orders.

Claims (11)

The claimed benefit is: 1. In a communication system where radio frequency signals are transmitted from a transmitting source with one antenna and received at a receiving unit with a second antenna, a method to reduce the effects of fading conditions in the radio frequency signal at the receiving unit consists of the following steps: detecting fading conditions in the radio frequency signal; monitoring the radio frequency signal for power limiting conditions occurring at the transmitting source; and modifying the antenna characteristics of the communication system when such power limiting and fading conditions occur. 2. The method described in claim 1 for altering the antenna characteristics of the said communication system is to alter the characteristics of at least one of the first and second antennas. 3. As described in Reputation 1, the procedure for detecting the quality of the radio frequency signal at the receiving unit considers the fading condition. 4. The method described in claim 3, where the quality is stated as the bit error rate of the radio frequency signal. 5. The method of Claim 1, where the power limitation condition is one of the power saturation conditions and the maximum transmission limit condition that has been predetermined. 6. The method described in Claim 1, under the aforementioned power limiting condition, is one in which the transmission source is unable to respond to power boost orders at a point of transition combined with the cumulative number of power boost orders, and at that point of transition combined with the cumulative number of power boost orders over a period of time. 7. The method described in Claim 1 is used to perform the aforementioned monitoring procedure in the receiving unit. 8. The methods described in claim 7 also include sending messages specifying such transmission power limitations. 9. The method described in Claim 1 is used to perform the aforementioned monitoring procedure at the origin of the transmission. 10. In a communication system, a controller regulates the power level of the transmitted signal and consists of: a receiver to capture the power control bit; a transmitter to output the transmitted signal at the specified power level in response to the power control bit; and a start-up signal generator that creates a control signal indicating changes in the antenna characteristics of the communication system. This control occurs when the power level and transmitted signal reach a limit and signal fading occurs. 11. The method described in claim 10 generates the control signal when such receiver detects multiple power control bits, and these multiple power control bits have a number of power increase instructions that exceed one start point in a given time period (Clause 11, page 2, figure 5).