Apparatus and method for discriminating information transmitted using radio signal

A signal discrimination device, which is used in a mobile communications system for transmitting a radio signal from a first device to a second device, for determining whether the radio signal indicates first information or second information, comprising:

• a demodulation unit demodulating a received radio signal;
• a threshold generation unit selecting base on a communications environment one of a first rule for generating a threshold such that a probability that it is mistakenly determined that the radio signal indicates the second information although the radio signal actually indicates the first information can be equal to or smaller than a predetermined value and a second rule for generating a threshold such that a probability that it is mistakenly determined that the radio signal indicates the first information although the radio signal actually indicates the second information can be equal to or smaller than a predetermined value, and generating a threshold according to the selected rule;
• and
• a determination unit determining whether the radio signal indicates the first information or the second information based on a result of comparing output of said demodulation unit with a threshold generated by said threshold generation unit.

A signal discrimination device, which is used in a mobile communications system for transmitting a radio signal from a first device to a second device, for determining whether the radio signal indicates first information or second information, comprising:

• a demodulation unit demodulating a received radio signal;
• a threshold generation unit generating a threshold based on an amount of noise of the radio signal and receiving power of the radio signal;
• and
• a determination unit determining whether the radio signal indicates the first information or the second information based on a result of comparing output of said demodulation unit with a threshold generated by said threshold generation unit.

A signal discrimination device for use in a communications system in which a first communications device transmits to a second communications device a connection request containing identification information identifying the first communications device, and the second communications device returns to the first communications device the identification information at a predetermined timing when communications corresponding to the connection request are enabled, comprising:

• a multiplier multiplying a received signal at the predetermined timing by the identification information in the first communications device;
• an integrator integrating output of said multiplier;
• a threshold generation unit selecting based on a communications environment one of a first rule for generating a threshold depending on an amount of noise of the received signal and a second rule for generating a threshold based on power or amplitude of the received signal, and generating a threshold according to selected rule;
• and
• a discrimination unit determining whether or not the communications corresponding to the connection request have been enabled based on a result of comparing output of said integrator with a threshold generated by said threshold generation unit.

A signal discrimination device for use in a communications system in which a first communications device transmits to a second communications device a connection request containing identification information identifying the first communications device, and the second communications device returns to the first communications device the identification information at a predetermined timing when communications corresponding to the connection request are enabled, comprising:

• a multiplier multiplying a received signal at the predetermined timing by the identification information in the first communications device;
• an integrator integrating output of said multiplier;
• an estimation unit estimating output of said integrator based on power or amplitude of the received signal;
• a threshold generation unit generating a threshold based on the estimated value;
• and
• a discrimination unit determining whether or not the communications corresponding to the connection request have been enabled based on a result of comparing output of said integrator with a threshold generated by said threshold generation unit.

A mobile station for use in a communications system in which the mobile station transmits to a base station a connection request including identification information identifying the mobile station, and the base station returns to the mobile station the identification information at a predetermined timing when communications corresponding to the connection request is enabled, comprising:

• a multiplier multiplying a received signal by the identification information at the predetermined timing;
• an integrator integrating output of said multiplier;
• a threshold generation unit selecting based on a communications environment one of a first rule for generating a threshold depending on an amount of noise of the received signal and a second rule for generating a threshold based on power or amplitude of the received signal, and generating a threshold according to selected rule;
• a discrimination unit determining whether or not the communications corresponding to the connection request have been enabled based on a result of comparing output of said integrator with a threshold generated by said threshold generation unit;
• and
• a control unit starting communications, when said discrimination unit determines that the communication are enabled.

A signal discriminating method, which is used in a mobile communications system for transmitting a radio signal from a first device to a second device, for determining whether the radio signal indicates first information or second information, comprising:

• demodulating a received radio signal;
• selecting depending on communications environment one of a first rule for generating a threshold depending on an amount of noise of the radio signal and a second rule for generating a threshold based on receiving power or receiving amplitude of the radio signal;
• generating a threshold according to the selected rule;
• and
• determining whether the radio signal indicates the first information or the second information based on a comparison result between demodulated signal obtained in said demodulating step and the threshold generated in said threshold generating step.

A signal discriminating method, which is used in a mobile communications system for transmitting a radio signal from a first device to a second device, for determining whether the radio signal indicates first information or second information, comprising:

• demodulating a received radio signal;
• generating a threshold based on an amount of noise of the radio signal and receiving power of the radio signal;
• and
• determining whether the radio signal indicates the first information or the second information based on a comparison result between demodulated signal obtained in said demodulating step and the threshold generated in said threshold generating step.