Multi-beam cellular base station, mobile station and method for sending spread spectrum signal

• US 20020177468A1
• Filed: 04/04/2002
• Published: 11/28/2002
• Est. Priority Date: 04/13/2001
• Status: Active Grant

• Current Assignee: KDDI Corporation
• Original Assignee: KDDI Corporation
• Inventors: Inoue, Takashi, Yamaguchi, Akira, Amano, Yoshiaki, Takeuchi, Yoshio
• Granted Patent: US 7,116,650 B2
• Time in Patent Office: Days
• US Class Current: 455/562.1
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A multi-beam cellular base station is for sending a spread spectrum signal to at least one mobile station, the base station comprising: first antenna for sending a common channel by a common beam that a directional pattern is formed previously; second antenna for sending a dedicated channel by a dedicated beam that a directional pattern is formed for each mobile station; and switching means for switching a sending time section of the common beam and a sending time section of the dedicated beam so that the sending time sections do not overlap within a time slot, the common beam and the dedicated beam are sent by same frequency.

Claims

1. A multi-beam cellular base station for sending a spread spectrum signal to at least one mobile station, said base station comprising:

first antenna for sending a common channel by a common beam that a directional pattern is formed previously;

second antenna for sending a dedicated channel by a dedicated beam that a directional pattern is formed for each mobile station; and

switching means for switching a sending time section of said common beam and a sending time section of said dedicated beam so that said sending time sections do not overlap within a time slot,

said common beam and said dedicated beam are sent by same frequency.

2. A multi-beam cellular base station as claimed in claim 1,

wherein said base station further comprising a dedicated beam forming means for adaptively forming said directional pattern of said dedicated beam sent from said second antenna for every time slot, corresponding to change of mobile station to be sent.

3. A multi-beam cellular base station as claimed in claim 1,

wherein said common channel including a common pilot channel,

wherein said dedicated channel including a dedicated traffic channel and a dedicated pilot channel, and

wherein said switching means sending to synchronize said dedicated traffic channel and said dedicated pilot channel for every mobile station.

4. A multi-beam cellular base station as claimed in claim 3,

wherein said base station further comprising means for spreading said dedicated pilot channel and said dedicated traffic channel for every mobile station by an mutually orthogonal code.

5. A multi-beam cellular base station as claimed in claim 1,

wherein said common channel including a common pilot channel,

wherein said dedicated channel including a dedicated traffic channel and a dedicated pilot channel, and

wherein said switching means sending said dedicated traffic channel and said dedicated pilot channel for every mobile station by time division multiplexing without overlapping in time.

6. A multi-beam cellular base station as claimed in claim 1,

wherein said multi-beam cellular base station further comprising means for spreading a plurality of dedicated channels by a same spreading code.

7. A mobile station for communicating with a multi-beam cellular base station for sending a spread spectrum signal, said multi-beam cellular base station comprising first antenna for sending a common channel by a common beam that a directional pattern is formed previously, second antenna for sending a dedicated channel by a dedicated beam that a directional pattern is formed for each mobile station, and switching means for switching a sending time section of said common beam and a sending time section of said dedicated beam so that said sending time sections do not overlap within a time slot, said common beam and said dedicated beam are sent by same frequency,

said mobile station comprising switching means for switching a received beam to said common channel or said dedicated channel based on a slot synchronization signal.

8. A mobile station as claimed in claim 7,

wherein said common channel including a common pilot channel, and said dedicated channel including a dedicated traffic channel and a dedicated pilot channel, and

wherein said mobile station further comprising:

estimation means for estimating a channel characteristic from said dedicated pilot channel received; and

demodulation means for demodulating said dedicated channel by using said estimated channel characteristic.

9. A cellular system comprising multi-beam cellular base stations and single beam cellular base stations, said multi-beam cellular base station having first antenna for sending a common channel by a common beam that a directional pattern is formed previously, second antenna for sending a dedicated channel by a dedicated beam that a directional pattern is formed for each mobile station, and switching means for switching a sending time section of said common beam and a sending time section of said dedicated beam so that said sending time sections do not overlap within a time slot, said common beam and said dedicated beam are sent by same frequency, and said single beam cellular base station sending said common channel and said dedicated channel by same directional pattern beam,

wherein said multi-beam cellular base station including a common pilot channel in said common channel, and including a dedicated traffic channel and a dedicated pilot channel in said dedicated channel, and

wherein said single beam cellular base station sending said dedicated traffic channel in a section of a data format, where said dedicated pilot channel is sent in the case of said multi-beam cellular base station, and sending a dedicated traffic channel data in a same section of a data format, where said dedicated traffic channel is sent in the case of multi-beam cellular base station.

10. A cellular system as claimed in claim 9,

wherein first transmission information bit rate and second transmission information bit rate are controlled to become equal, said first transmission information is included in signal of a dedicated traffic channel received from said multi-beam cellular base station, and said second transmission information is included in signal of a dedicated traffic channel received from said single beam cellular base station.

11. A mobile station for communicating with a cellular system comprising a multi-beam cellular base station and a single beam cellular base station,

said multi-beam cellular base station having first antenna for sending a common channel by a common beam that a directional pattern is formed previously, second antenna for sending a dedicated channel by a dedicated beam that a directional pattern is formed for each mobile station, and switching means for switching a sending time section of said common beam and a sending time section of said dedicated beam so that said sending time sections do not overlap within a time slot, said common beam and said dedicated beam are sent by same frequency, and

said single beam cellular base station sending said common channel and said dedicated channel by same directional pattern beam,

said mobile station comprising means for distinguishing whether said cellular base station for sending a signal is said multi-beam base station or said single beam base station, said signal is processed according to the identification.

12. A method for sending spread spectrum signal from cellular base station to a plurality of mobile stations, said method comprising the steps of:

sending a common channel for a predetermined time in every time slot, by a common beam that a directional pattern is formed previously; and

sending a dedicated channel for a time other than said predetermined time in every time slot, by a dedicated beam that a directional pattern is formed adaptively for each mobile station,

said common channel and said dedicated channel sent by same frequency are not overlap within a time slot.