Spread spectrum communication device and spread spectrum communication method

• US 20080069076A1
• Filed: 10/31/2007
• Published: 03/20/2008
• Est. Priority Date: 03/26/1998
• Status: Abandoned Application

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Murai, Hideshi, Yano, Yasuhiro
• Application Number:
  US11/980,566
• Publication Number:
  US 20080069076A1
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/7083 Cell search, e.g. using a three-step approach
• CPC Class Codes: H04B 1/7087 Carrier synchronisation aspects
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• 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 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/0047 Decoding adapted to other signal detection operation in conjunction with sequence estimation or equalization H04L25/03286
• CPC Class Codes: H04L 1/0056 Systems characterized by the type of code used H04L1/08 takes precedence
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0083 : Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04W 36/0088 : Scheduling hand-off measurements
• CPC Class Codes: H04W 36/302 : due to low signal strength
• CPC Class Codes: H04W 52/08 : Closed loop power control
• CPC Class Codes: H04W 52/267 : taking into account the information rate
• CPC Class Codes: H04W 52/28 : using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
• CPC Class Codes: H04W 52/287 : when the channel is in stand-by
• CPC Class Codes: H04W 52/288 : taking into account the usage mode, e.g. hands-free, data transmission, telephone
• CPC Class Codes: H04W 52/36 : with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/362 : Aspects of the step size
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/44 : in connection with interruption of transmission
• CPC Class Codes: H04W 52/48 : during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/56 : Detection of errors of TPC bits
• CPC Class Codes: H04W 52/60 : using different transmission rates for TPC commands
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements

Abstract

In a compressed mode, a spread spectrum communication device interleaves bit units across multiple frames using an interleaver, reduces the spreading factor using a framing/spreading unit, outputs the compressed mode frames at a predetermined compressed mode frame timing, and increases the average transmission power in the compressed mode at a radio frequency transmitter. Furthermore, a handover between different frequencies is carried out by establishing synchronization to another frequency carrier, based on a first search code and a second search code which have been detected, and moreover, a handover between different communication systems is carried out by establishing synchronization to a GSM, based on an FCCH and a SCH which have been detected.

Claims

1. A mobile communication system-in a code division multiple access system continuously transmitting uncompressed frames in a normal mode;

and intermittently transmitting compressed frames in a compressed mode, comprising,

a base station, including

a transmitting unit (15) that transmits transmission power control information to a mobile station, the power control information ctrotg indicating an increase or a decrease in transmission power; and

the mobile station, including

a receiving unit (25) configured to receive said transmission power control information indicating an increase or a decrease in power from the mcblc base station,

an interleaving unit (13) configured to perform interleaving in bit units on a frame,

a compressing unit (14) configured to compress a frame so as to produce a compressed frame in compressed mode,

a transmitting unit (15) configured to transmit frames, and

a control unit (11) configured to control said interleaving unit (13), said compressing unit (14), and said transmitting unit (15);

characterized in that said interleaving unit (13), said compressing unit (14), and said transmitting unit (15) are configured to be controlled so as to

provide an idle period in which a frame is not transmitted and which is used to observe other frequency career, by dividing the compressed frame into a front portion of a frame window and a rear portion separated from the front portion, in order to produce a divided frame in which said front portion has a front edge of a frame window and said rear portion has a rear edge of said frame window,

adjust transmission power on the uncompressed and compressed frames in accordance with the transmission power control information, by increasing or decreasing current power with a power control step size for the uncompressed frame and with a plurality of power control step sizes for the compressed frames, and

transmit the uncompressed or compressed frames in accordance with the adjusted transmission power.

2. A mobile communication system in a code division multiple access system continuously transmitting uncompressed frames in a normal mode;

and intermittently transmitting compressed frames in a compressed mode, comprising,

a mobile station, including

a transmitting unit (15) that transmits transmission power control information to a base station, the power control information indicating an increase or a decrease in transmission power; and

the base station, including

a receiving unit (25) configured to receive said transmission power control information indicating an increase or a decrease in power from the mobile station,

an interleaving unit (13) configured to perform interleaving in bit units on a frame,

a compressing unit (14) configured to compress a frame so as to produce a compressed frame in compressed mode,

a transmitting unit (15) configured to transmit frames, and

a control unit (11) configured to control said interleaving unit (13), said compressing unit (14), and said transmitting unit (15);

characterized in that said interleaving unit (13), said compressing unit (14), and said transmitting unit (15) are configured to be controlled so as to

provide an idle period in which a frame is not transmitted and which is used to observe other frequency career, by dividing the compressed frame into a front portion of a frame window and a rear portion separated from the front portion, in order to produce a divided frame in which said front portion has a front edge of a frame window and said rear portion has a rear edge of said frame window,

adjust transmission power on the uncompressed and compressed frames in accordance with the transmission power control information, by increasing or decreasing current power with a power control step size for the uncompressed frame and with a plurality of power control step sizes for the compressed frames, and transmit the uncompressed or compressed frames in accordance with the adjusted transmission power.

3. A base station in a code division multiple access system continuously transmitting uncompressed frames in a normal mode;

and intermittently transmitting compressed frames in a compressed mode, comprising,

a receiving unit (25) configured to receive transmission power control information indicating an increase or a decrease in power from a mobile station,

an interleaving unit (13) configured to perform interleaving in bit units on a frame,

a compressing unit (14) configured to compress a frame so as to produce a compressed frame in compressed mode,

a transmitting unit (15) configured to transmit frames, and

a control unit (11) configured to control said interleaving unit (13), said compressing unit (14), and said transmitting unit (15);

characterized in that said interleaving unit (13), said compressing unit (14), and said transmitting unit (15) are configured to be controlled so as to

provide an idle period in which a frame is not transmitted and which is used to observe other frequency career, by dividing the compressed frame into a front portion of a frame window and a rear portion separated from the front portion, so as to produce a divided frame in which said front portion has a front edge of a frame window and said rear portion has a rear edge of said frame window,

adjust transmission power on the uncompressed and compressed frames in accordance with the transmission power control information, by increasing or decreasing current power with a power control step size for the uncompressed frame and with a plurality of power control step sizes for the compressed frames, and

transmit the uncompressed or compressed frames in accordance with the adjusted transmission power.

4. A mobile station in a code division multiple access system continuously transmitting uncompressed frames in a normal mode;

and intermittently transmitting compressed frames in a compressed mode, comprising,

a receiving unit (25) configured to receive transmission power control information indicating an increase or a decrease in power from a base station,

an interleaving unit (13) configured to perform interleaving in bit units on a frame,

a compressing unit (14) configured to compress an interleaved frame so as to produce a compressed frame in compressed mode,

a transmitting unit (15) configured to transmit frames, and

a control unit (11) configured to control said interleaving unit (13), said compressing unit (14), and said transmitting unit (15);

characterized in that said interleaving unit (13), said compressing unit (14), and said transmitting unit (15) are configured to be controlled so as to

provide an idle period in which a frame is not transmitted and which is used to observe other frequency career, by dividing the compressed frame into a front portion of a frame window and a rear portion separated from the front portion, in order to produce a divided frame in which said front portion has a front edge of a frame window and said rear portion has a rear edge of said frame window,

adjust transmission power on the uncompressed and compressed frames in accordance with the transmission power control information, by increasing or decreasing current power with a power control step size for the uncompressed frame and with a plurality of power control step sizes for the compressed frames, and transmit the uncompressed or compressed frames in accordance with the adjusted transmission power.