Abstract: A transmitter communicating with a receiver, the transmitter including: a first hopping sequence generation unit which generates a hopping sequence whose hopping subcarrier interval is less than or equal to a predetermined threshold value based on a cell ID; a first reference signal pattern generation unit which generates a reference signal pattern based on a reference signal basic pattern including a predetermined known signal sequence and the hopping sequence generated by the first hopping sequence generation unit; an arrangement unit which arranges the reference signal and a data symbol in a predetermined position within the symbol, based on the reference signal pattern generated by the first reference signal pattern generation unit; and a signal transmission unit which transmits the symbol having the reference signal and the data symbol arranged by the arrangement unit to the receiver.

Abstract: A transmitter communicating with a receiver, the transmitter including: a first hopping sequence generation unit which generates a hopping sequence whose hopping subcarrier interval is less than or equal to a predetermined threshold value based on a cell ID; a first reference signal pattern generation unit which generates a reference signal pattern based on a reference signal basic pattern including a predetermined known signal sequence and the hopping sequence generated by the first hopping sequence generation unit; an arrangement unit which arranges the reference signal and a data symbol in a predetermined position within the symbol, based on the reference signal pattern generated by the first reference signal pattern generation unit; and a signal transmission unit which transmits the symbol having the reference signal and the data symbol arranged by the arrangement unit to the receiver.

Abstract: A transmitter which communicates with a receiver. The transmitter includes a null subcarrier allocation unit which allocates a null subcarrier based on a priority and a signal. The priority is for allocating a null subcarrier to each subcarrier. The priority is a ranking predetermined with the receiver. The signal is allocated to each subcarrier. The transmitter includes a transmission unit which transmits the signal using the subcarrier allocated by the null subcarrier allocation unit as the null subcarrier to the receiver.

Abstract: A small antenna device having an increased gain is provided. The antenna device includes a multilayer dielectric substrate composed of a combination of a plurality of dielectric layers, wherein a feeding antenna is provided in a lower layer of the multilayer substrate, a reflective metal plate is provided above the feeding antenna, and circular or rectangular metal loops are arranged so as to be of increasing diameter from lower layers toward upper layers in the plurality of dielectric layers.

Abstract: A small antenna device having an increased gain is provided. The antenna device includes a multilayer dielectric substrate composed of a combination of a plurality of dielectric layers, wherein a feeding antenna is provided in a lower layer of the multilayer substrate, a reflective metal plate is provided above the feeding antenna, and circular or rectangular metal loops are arranged so as to be of increasing diameter from lower layers toward upper layers in the plurality of dielectric layers.

Abstract: A pair of bands are each secured at one end to one side of a case wherein a radio receiver is housed, and a monopole antenna having a length of 0.005.lambda. has one end connected to the feeding point of the radio receiver and its other end exposed to the outside of the case to form a contact portion for contact with the human body. A first helical antenna is supported to the one of the bands lengthwise thereof and is connected at one end to the feeding point. A second helical antenna is supported to the other band lengthwise thereof and is connected at one end to the common potential point of the radio receiver. The first and second helical antennas resonate, as one antenna, with the wavelength .lambda. used by the radio receiver, and their pitch P and helix area A are selected so that P<500A/.lambda. and P>150A/.lambda..