Directivity control type communication apparatus and adaptive array antenna apparatus

A directional transmission method for selecting a signal from among signals received under multipath environment, and using a path corresponding to a selected signal as a path for signal transmission, said method comprising the steps of:

• monitoring a transmit power control command (TPC) returned from a communication apparatus of a communication partner;
• referring to a history of said transmit power control command (TPC) in judging whether or not to switch the path for signal transmission;
• and
• switching the path for signal transmission by changing a current transmission radiation pattern when it is estimated as a result of referring that a previous reception condition in said communication apparatus of the communication partner is not good.

A directional transmission method using an adaptive array antenna, said method comprising the steps of:

• monitoring a transmit power control command (TPC) returned from a communication apparatus of a communication partner;
• referring to a history of said transmit power control command (TPC) in judging whether or not to switch a path for signal transmission;
• and
• switching the path for signal transmission by changing a current transmission radiation pattern when it is estimated as a result of referring that a previous reception condition in said communication apparatus of the communication partner is not good.

A directivity control type communication apparatus comprising:

• a directional reception circuit that receives a multiplexed signal transmitted under multipath phenomenon while controlling a reception directivity, and demodulates a signal for each of a plurality of paths;
• reception directivity information selection section that determines which reception directivity information is used to form a transmission radiation pattern among the reception directivity information for each path used in demodulating said signal, by referring to information indicative of a previous reception condition in a communication apparatus of a communication partner transmitted from said communication apparatus of the communication partner;
• and
• a directional transmission section that forms a transmission radiation pattern based on the reception directivity information outputted from said reception directivity information selection section to perform directional transmission.

The directivity control type communication apparatus further comprising:

• a buffer that stores information indicative of a previous reception condition in said communication apparatus of the communication partner previously transmitted from said communication apparatus of the communication partner;
• a transmission path determination section that determines a path for signal transmission by referring to the information indicative of said reception condition stored in said buffer;
• and
• a selection section that selects the reception directivity information corresponding to a path determined by said transmission path determination section to output to said directional transmission section.

An adaptive array antenna apparatus comprising:

• a plurality of antenna elements;
• a directional reception circuit that forms a reception directivity for each path while adaptively varying a value of a weight to be multiplied a signal received at each of said plurality of antenna elements, and demodulates a signal for each path;
• a buffer that stores a transmit power control command (TPC) transmitted from a communication partner;
• a transmission path determination section that determines a path for signal transmission by referring to information indicative of a reception condition stored in said buffer;
• a selection section that selects a value of the weight corresponding to a path determined by said transmission path determination section to output;
• and
• a directional transmission section that forms a transmission radiation pattern based on information on said value of the weight outputted from said selection section to perform directional transmission.