CDMA mobile communication system and communication method

• US 7,154,875 B2
• Filed: 12/21/2001
• Issued: 12/26/2006
• Est. Priority Date: 08/10/1995
• Status: Expired due to Fees

• Current Assignee: FIPA Frohwitter Intellectual Property AG
• Original Assignee: Hitachi, Ltd.
• Inventors: Doi, Nobukazu, Yano, Takashi, Masui, Hironari, Ohgoshi, Yasuo
• Primary Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US10/023,737
• Publication Number:
  US 20020071412A1
• Time in Patent Office: 1,831 Days
• Field of Search: None
• US Class Current: 370/342
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 7/2637 for logical channel control
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
• CPC Class Codes: H04W 74/085 collision avoidance

Abstract

A radio communication system having a base station and a plurality of radio terminals, wherein each radio terminal having a transmission request transmits a reservation packet at arbitrary timing through a reservation channel in accordance with a CDMA scheme, and the base station assigns a traffic channel and a time slot to be used to each radio terminal requesting a reservation through a reply packet outputted onto a reply channel. On the reservation channel, a short spreading code corresponding to a matched filter is applied.

Claims

1. A system comprising:

a base station; and

a plurality of terminals,

wherein a terminal having a request for data transmission transmits a reservation packet to said base station,

said base station, having received said reservation packet, transmits a reply packet to said terminal which transmitted said reservation packet, said reply packet being processed with a spreading code, and

wherein said base station generates a busy tone signal to control transmission of reservation packets from said plurality of terminals, and transmits said busy tone signal processed with a same spreading code which is used to process said reply packet.

2. A base station in a system comprising said base station, and a plurality of terminals, wherein a terminal having a request for data transmission transmits a reservation packet to said base station, comprising:

a reply packet constructing unit for, in response to receiving said reservation packet from a terminal, transmitting a reply packet to said terminal which transmitted said reservation packet; and

a busy tone value calculator for generating and notifying a busy tone signal to control transmission of reservation packets from said plurality of terminals,

wherein said reply packet and said busy tone signal are processed using a same spreading code.

3. A terminal in a system comprising a base station, and a plurality of terminals, comprising:

a reservation packet constructing unit for, when having a request for data transmission, constructing a reservation packet to be transmitted to said base station;

a busy tone value calculator which receives from a base station a busy tone signal to control transmission of reservation packets;

an upward schedule controller which receives traffic state information from said busy tone value calculator to control issuance of reservation packets; and

means for receiving a reply packet transmitted from said base station in response to said reservation packet,

wherein, at receiving, said busy tone signal and said reply packet are despread using a same spreading code.

4. A wireless communication system comprising a base station and a plurality of terminals each for transmitting data to said base station using one of a plurality of transmission channels for said base station,

wherein a terminal having a request for data transmission transmits a reservation packet to said base station,

wherein said base station, in response to a reception of said reservation packet, transmits a reply packet for said terminal which transmitted said reservation jacket, and

wherein said base station generates a busy tone signal to control transmission of reservation packets from said plurality of terminal based on a condition of said transmission channel, spreads said busy tone signal using a same spreading code as said reply packet, and transmits said busy tone signal in a designated timing of slots of a control channel which is a CDMA channel used for control of said plurality of transmission channels.

5. The wireless communication system according to claim 4, wherein said plurality of transmission channels and a channel used to transmit said reservation packet are CDMA channels.

6. A base station in a wireless communication system comprising a base station and a plurality of terminals each for transmitting data to said base station using one of a plurality of transmission channels for said base station, comprising:

a reply packet generator which generates a reply packet in response to reception of a reservation packet from a terminal, and transmits said reply packet for said terminal; and

a busy tone value calculator which generates and notifies a busy tone signal to control transmission of reservation packets from said plurality of terminal, based on a condition of said transmission channel,

wherein said reply packet and said busy tone signal are spread using a same spreading code, and transmitted using designated timings in slots on a CDMA control channel used for control of said plurality of transmission channels.

7. The base station according to claim 6, wherein said plurality of transmission channels and a channel used to transmit said reservation packet are CDMA channels.

8. A terminal in a wireless communication system comprising a base station and a plurality of terminals each for transmitting data to said base station using one of a plurality of transmission channels for said base station, comprising:

a reservation packet generator which generates a reservation packet when there is data to be transmitted;

a uplink schedule controller which controls transmission of said reservation packet according to a busy tone signal received from said base station, which is used to control said transmission of reservation packets based on a condition of said plurality of transmission channels; and

a reception unit which receives a reply packet transmitted from said base station in response to said reservation packet,

wherein said reception unit despreads said busy tone signal and said reply packet using a same spreading code, and said busy tone signal and said reply packet axe received at timings in slots on a CDMA control channel used for control of said plurality of transmission channels.

9. The terminal according to claim 8, wherein said plurality of transmission channels and a channel used to transmit said reservation packet are CDMA channels.