Radio apparatus and communication system utilizing the same

• US 20070076582A1
• Filed: 09/19/2006
• Published: 04/05/2007
• Est. Priority Date: 09/20/2005
• Status: Active Grant

• Current Assignee: Hera Wireless S.A. (Fineur International S.A.)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Tanaka, Yasuhiro, Nakao, Seigo
• Granted Patent: US 8,385,255 B2
• Time in Patent Office: Days
• US Class Current: 370/203
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2613 Structure of the reference signals

Abstract

Using as a reference a known signal assigned to one of a plurality of streams that constitute a packet signal, a control unit applies a cyclic timing shift to known signals assigned to the other streams so as to produce packet signals which are to be transmitted finally. While varying the amount of timing shift, the control unit produces a plurality of packet signals and appends an identification number, with which to uniquely identify each of the plurality of produced packet signals, to each of the packet signals. A baseband processing unit and the like transmit, as a transmission rate inquiry signal, a packet signal constituted by a plurality of streams where the amounts of timing shift are made to differ, and receive a response signal to which the same identification number is appended for the inquiry signal.

Claims

1. A radio apparatus for transmitting a packet signal composed of a plurality of streams, the apparatus comprising:

a generation unit which uses as a reference a known signal assigned to one of a plurality of streams forming a packet signal and generates a packet signal to be finally transmitted, by applying a cyclic timing shift within the known signal to a known signal assigned to another stream; and

a communication unit which transmits the packet signal generated by said generation unit,

wherein said generation unit generates a plurality of packet signals by varying an amount of the timing shift and appends an identification number with which to uniquely identify each of the plurality of generated packet signals, to the each packet signal and

wherein said communication unit transmits a packet signal, composed of the plurality of streams, whose timing shift amount is made to differ and to which the identification number is appended, as an inquiry signal on a transmission rate, and receives a response signal to which the same identification number as the inquiry signal is appended.

2. A radio apparatus according to claim 1, further comprising an extension unit which extends the number of streams, forming a packet signal, by multiplying the packet signal by an orthogonal matrix,

wherein said generation unit applies the timing shift to a plurality of streams forming the packet signal whose number of streams has been extended.

3. A radio apparatus for transmitting packet signals from a plurality of antennas, the apparatus comprising:

a generation unit which generates a packet signal that contains a known signal; and

a communication unit which transmits the packet signal generated by said generation unit from any of the plurality of antennas,

wherein said generation unit appends an identification number for uniquely identifying an antenna from which the packet signal is transmitted, to the packet signal and

wherein said communication unit transmits the packet signal to which the identification number has been appended, as an inquiry signal on a transmission rate, and receives a response signal to which the same identification number as the inquiry signal is appended.

4. A radio apparatus for receiving packet signals, the apparatus comprising:

a receiver which receives an inquiry signal, on a transmission rate, to which an identification number has been appended;

a determination unit which determines a transmission rate based on a received signal;

a generation unit which generates a packet signal that contains information on the determined transmission rate and the identification number appended to the inquiry signal; and

a transmitter which sends back the packet signal generated by said generation unit, as a response signal to the inquiry signal.

5. A radio apparatus according to claim 4, wherein said determination unit determines the transmission rate based on a received power.

6. A communication system, comprising:

a transmitting apparatus which transmits a packet signal composed of a plurality of streams; and

a receiving apparatus which receives the packet signal transmitted from said transmitting apparatus,

said transmitting apparatus including;

a first generation unit which uses as a reference a known signal assigned to one of a plurality of streams forming a packet signal and generates a packet signal to be finally transmitted, by applying a cyclic timing shift within the known signal to a known signal assigned to another stream; and

a communication unit which transmits the packet signal generated by the first generation unit,

wherein the first generation unit generates a plurality of packet signals by varying an amount of the timing shift and appends an identification number with which to uniquely identify each of the plurality of generated packet signals, to the each packet signal and

wherein the communication unit transmits a packet signal, composed of the plurality of streams, whose timing shift amounts are made to differ and to which the identification number are appended, as an inquiry signal on a transmission rate,

said receiving apparatus including;

a receiver which receives the inquiry signal to which the identification number has been appended;

a determination unit which determines a transmission rate based on a received signal;

a second generation unit which generates a packet signal that contains information on the determined transmission rate and the identification number appended to the inquiry signal; and

a transmitter which sends back the packet signal generated by the second generation unit, as a response signal to the inquiry signal.

7. A communication system, comprising:

a transmitting apparatus which transmits a packet signal from a plurality of antennas; and

a receiving apparatus which receives the packet signal transmitted from said transmitting apparatus,

said transmitting apparatus including;

a first generation unit which generates a packet signal that contains a known signal; and

a communication unit which transmits the packet signal generated by the first generation unit from any of the plurality of antennas,

wherein the first generation unit appends an identification number for uniquely identifying an antenna from which the packet signal is transmitted, to the packet signal and

wherein the communication unit transmits the packet signal to which the identification number has been appended, as an inquiry signal on a transmission rate, to said receiving apparatus,

said receiving apparatus including;

a receiver which receives the inquiry signal to which the identification number has been appended;

a determination unit which determines a transmission rate based on a received signal;

a second generation unit which generates a packet signal that contains information on the determined transmission rate and the identification number appended to the inquiry signal; and

a transmitter which sends back the packet signal generated by the second generation unit, as a response signal to the inquiry signal.