Method for determining transmission power

Abstract

There is a provided a method for deciding transmission power in order to transmit at least one of secret data and non-secret data. The method may comprise: determining whether data to be transmitted by a transmitting device is sensitive to a delay; determining whether both the secret data and the non-secret data are required to be simultaneously transmitted when the data to be transmitted is sensitive to the delay; and applying different weights to the secret data and the non-secret data and deciding transmission power to maximize a total channel capacity according to the application, when it is determined that both the secret data and the non-secret data are required to be transmitted.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of priority of U.S. Provisional applications No. 61 / 719,524 filed on Oct. 29, 2012, all of which is incorporated by reference in their entirety herein.TECHNICAL FIELD[0002]The present invention relates to a method for determining transmission power.BACKGROUND ART[0003]FIG. 1 illustrates a wireless communication system.[0004]As seen with reference to FIG. 1, the wireless communication system includes at least one base station (BS) 20. Each base station 20 provides a communication service to specific geographical areas (generally, referred to as cells) 20a, 20b, and 20c. The cell can be further divided into a plurality of areas (sectors). A terminal (user equipment, UE) 10 may be fixed or movable and may be called other terms such as a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), a wireless modem, a han...

AI Technical Summary

Benefits of technology

[0013]The method may further comprise: determining whether both the secret data and the non-secret data are required to be simultaneously transmitted when it is determined that the data to be transmitted is not sensitive to the delay; deciding optimal transmission power by minimizing an outage probability when target secret transmission rate Rs is given in the case where it is determined that only the secret data is required to be transmitted; and deciding the target secret transmission rate Rs in order to maximize a system throughput.

[0014]The method may further comprise: calculating the outage probability by considering both the non-secret data and the secret data when it is determined that the data to be transmitted is not sensitive to the delay and it is determined that both the secret data and the non-secret data are required to be transmitted; and deciding transmission power to minimize the outage probability.

[0015]The method may further comprise: calculating the outage probability for each of the non-secret data and the secret data when it is determined that the data to be transmitted is not sensitive to the delay and it is determined that both the secret data and the non-secret data are required to be transmitted; and deciding transmission power to minimize the outage probability for the secret data while ensuring a maximum value of the outage probability for the non-secret data.

[0020]When the transmission power of the wireless communication system is optimized by the methods proposed in the present invention, the following effects are obtained. When transmitted data is not sensitive to a transmission delay, an ergodic channel capacity can be maximized by optimizing the transmission power. In particular, when both non-secret data and secret data are transmitted, different weights are given to two different types to optimize the transmission power, thereby adjusting a non-secret channel capacity value and a secret channel capacity value.

[0021]When the transmitted data is sensitive to the transmission delay, an outage probability can be minimized by optimizing the transmission power. When the outage probability is minimized, an outage probability considering both the non-secret data and the secret data may be minimized, only an outage probability for the non-secret data may be minimized, or only an outage probability for the secret data may be minimized. Further, instead of an optimal power distribution that minimizes the outage probability, target transmission rate at a receiver may be optimized so as to maximize a system throughput.

[0022]Last, when only some of the transmitted data is sensitive to the transmission delay, the ergodic channel capacity can be maximized while preventing the outage probability from being increased to a predetermined reference value or more by optimizing the transmission power. The optimization of the transmission power can be performed in all of a case in which only the non-secret data is transmitted, a case in which only the secret data is transmitted, and a case in which both the secret data and the non-secret data are transmitted.

Problems solved by technology

However, when the transmission power is increased, since the transmission power is overheard by a third person, the transmission power may not be thoughtlessly increased.

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