Wireless transmission system and wireless transmission method and wireless station for use therein

A wireless transmission system comprising:

• a plurality of wireless stations able to transmit packets, and having a path diversity system formed by a transmitter-side wireless station, a multi-path channel, and a receiver-side wireless station, each wireless station including:
• a delay amount determining section for randomly selecting a delay amount from among a plurality of candidate values as a delay amount for which to delay a packet transmission;
• a transmission timing control section for determining a transmission start timing to start the packet transmission, the transmission start timing being obtained by delaying a reference timing by the delay amount selected by the delay amount determining section, the reference timing being a reference for the packet transmission;
• a transmitting section for transmitting the packet at the transmission start timing determined by the transmission timing control section;
• and
• a receiving section for receiving a packet to be transmitted to another wireless station,
• wherein a difference between any two candidate values of the plurality of candidate values is greater than or equal to a predetermined delay resolution, and a difference between a maximum candidate value of the plurality of candidate values and a minimum candidate value of the plurality of candidate values is less than or equal to a predetermined maximum delay, and
• wherein the predetermined delay resolution and the predetermined maximum delay are set to values such that a plurality of delayed waves can be received with path diversity.

A method for transmitting a packet from a wireless station for use in a system having a plurality of wireless stations able to transmit packets, and having a path diversity system formed by a transmitter-side wireless station, a multi-path channel, and a receiver-side wireless station, the method comprising the steps of:

• randomly selecting a delay amount from among a plurality of candidate values as a delay amount for which to delay a packet transmission;
• determining a transmission start timing to start the packet transmission, the transmission start timing being obtained by delaying a reference timing by the delay amount selected in the step of randomly selecting a delay amount, the reference timing being a reference for the packet transmission;
• and
• transmitting the packet at the transmission start timing determined in the step of determining a transmission start timing,
• wherein a difference between any two candidate values of the plurality of candidate values is greater than or equal to a predetermined delay resolution, and a difference between a maximum candidate value of the plurality of candidate values and a minimum candidate value of the plurality of candidate values is less than or equal to a predetermined maximum delay, and
• wherein the predetermined delay resolution and the predetermined maximum delay are set to values such that a plurality of delayed waves can be received with path diversity.

A method for use in a system in which a plurality of wireless stations transmit the same packet at a predetermined timing, wherein a path diversity system is formed by a transmitter-side wireless station, a multi-path channel, and a receiver-side wireless station, the method comprising the steps of:

• randomly selecting a delay amount from among a plurality of candidate values as a delay amount for which to delay a packet transmission;
• determining a transmission start timing to start the packet transmission, the transmission start timing being obtained by delaying a reference timing by the delay amount selected in the step of randomly selecting a delay amount, the reference timing being a reference for the packet transmission;
• transmitting the packet to a recipient wireless station at the transmission start timing determined in the step of determining a transmission start timing;
• and
• receiving a packet transmitted from another wireless station,
• wherein a difference between any two candidate values of the plurality of candidate values is greater than or equal to a predetermined delay resolution, and a difference between a maximum candidate value of the plurality of candidate values and a minimum candidate value of the plurality of candidate values is less than or equal to a predetermined maximum delay, and
• wherein the predetermined delay resolution and the predetermined maximum delay are set to values such that a plurality of delayed waves can be received with path diversity.