Power control device and method for controlling a reverse link common channel in a CDMA communication system

• US 20030026219A1
• Filed: 09/30/2002
• Published: 02/06/2003
• Est. Priority Date: 03/23/1998
• Status: Active Grant

• Current Assignee: Hi-Chan Moon, Hyun-Suk Lee, Jae-Min Ahn, Jin-Woo Choi, Young-Ky Kim
• Original Assignee: Hi-Chan Moon, Hyun-Suk Lee, Jae-Min Ahn, Jin-Woo Choi, Young-Ky Kim
• Inventors: Choi, Jin-Woo, Moon, Hi-Chan, Kim, Young-Ky, Ahn, Jae-Min, Lee, Hyun-Suk
• Granted Patent: US 7,480,275 B2
• Time in Patent Office: Days
• US Class Current: 370/318
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/14 Separate analysis of uplink or downlink
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/322 Power control of broadcast channels
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure
• CPC Class Codes: H04W 52/58 Format of the TPC bits
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A common power control channel transmission device for a base station in a CDMA communication system is provided having a selector for receiving power control commands to be transmitted to multiple subscribers and multiplexing the received power control commands; and a spreading modulator for spreading an output of the selector by multiplying the output of the selector by a spreading sequence. The common power control channel transmission device can be used to control power of a reverse link common channel. For the power control of the reverse link common channel, the base station receives a signal from a mobile station via the reverse link common channel, and transmits to the mobile station a power control command for controlling a transmission power of the reverse link common channel according to a measured strength of the received signal.

Claims

1. A common power control channel transmission device for a base station in a CDMA communication system, comprising:

a selector for receiving power control commands to be transmitted to multiple subscribers and multiplexing the received power control commands; and

a spreading modulator for spreading an output signal from the selector by multiplying the output signal of the selector by a spreading sequence and transmitting the spread signal.

2. The common power control channel transmission device as claimed in claim 1, further comprising a slot controller for controlling the selector so that the power control commands for the respective subscribers, outputted from the selector, are pseudo-randomly arranged in each power control group.

3. The common power control channel transmission device as claimed in claim 2, wherein said slot controller comprises a look-up table for storing a slot hopping pattern for positioning the power control commands at corresponding slots on the common power control channel.

4. The common power control channel transmission device as claimed in claim 1, wherein the common power control channel is used by multiple subscribers on a time-shared basis.

5. The common power control channel transmission device as claimed in claim 1, further comprising scramblers connected between a node for receiving the power control commands and the selector, for scrambling the power control commands by multiplying the power control commands by corresponding user'"'"'s pseudo-random noise (PN) sequences assigned to the respective subscribers.

6. The common power control channel transmission device as claimed in claim 1, further comprising an orthogonal modulator for orthogonally modulating an output of the selector by multiplying the output of the selector by an orthogonal code for the common power control channel.

7. The common power control channel transmission device as claimed in claim 1, wherein said orthogonal modulator and spreading modulator have a quadrature phase shift keying (QPSK) scheme.

8. The common power control channel transmission device as claimed in claim 2, further comprising gain controllers for independently controlling gains of the respective power control commands.

9. The common power control channel transmission device as claimed in claim 8, wherein the gain controllers have independent gains to independently provide the gains to the common power control channel according to the subscribers.

10. A method for transmitting a power control command to control a power of a reverse link in a base station for a CDMA communication system, comprising the steps of:

multiplexing power control commands generated for corresponding multiple subscribers; and

spreading the multiplexed power control commands by multiplying the multiplexed power control commands by a spreading sequence, and transmitting the spread multiplexed power control commands via the common power control channel.

11. The base station device as claimed in claim 10, further comprising the step of scrambling the power control commands with corresponding user'"'"'s PN sequences assigned to the respective subscribers, prior to multiplexing.

12. The method as claimed in claim 10, wherein in said multiplexing step, the power control commands for the respective subscribers are multiplexed in such a manner that the power control commands are arranged at pseudo-randomized positions in the respective power control groups.

13. The method as claimed in claim 12, further comprising the step of controlling gains of the power control commands, prior to multiplexing.

14. The method as claimed in claim 12, further comprising the step of orthogonally modulating the multiplexed power control commands with the orthogonal code for the common power control channel.

15. A channel receiver for a mobile station in a CDMA communication system, comprising:

a despreader for dispreading a spread power control command received from a base station via a common power control channel by multiplying the spread power control command by a spreading sequence;

a position selector for generating a position select signal; and

means for selectively outputting the received power control commands according to the position select signal.

16. A channel receiving device for a mobile station in a CDMA communication system, comprising:

a despreader for dispreading a received spread signal;

a first orthogonal code generator for generating a first orthogonal code for demodulating symbol data on a subscriber channel out of the despread signal;

a second orthogonal code generator for generating a second orthogonal code for demodulating a power control command, out of the despread signal, received from a base station via a common power control channel;

a first orthogonal demodulator for orthogonally demodulating the despread signal by multiplying the despread signal by an output of the first orthogonal code generator;

a second orthogonal demodulator for orthogonally demodulating the despread signal by multiplying the despread signal by an output of the second orthogonal code generator;

a position selector for generating a position select signal;

a first switch for connecting the first or second orthogonal code to the first or second orthogonal demodulator according to the position select signal; and

a second switch connected to receive outputs of the first and second orthogonal demodulators, for transferring subscriber channel symbol data output from the first orthogonal demodulator to a data combiner or transferring the power control command output from the second orthogonal demodulator to a power control command combiner according to the position select signal.

17. The channel receiving device as claimed in claim 16, wherein the position select signal is used to detect a slot on the power control command channel, into which the power control command for the corresponding subscriber channel is inserted.

18. A method for receiving channel data in a mobile station for a CDMA communication system, comprising the steps of:

receiving spread power control commands from multiple base stations via a common power control channel;

dispreading the receiver power control commands; and

selectively detecting the despread power control commands based on time slots previously assigned to the respective subscribers.

19. The method as claimed in claim 18, wherein said dispreading step comprises the steps of:

dispreading the received signal with a spreading sequence; and

demodulating the despread signal with an orthogonal code.

20. A channel receiving device for a mobile station in a CDMA communication system, comprising:

a despreader for dispreading spread power control commands received from a base station via a common power control channel to control a power of a reverse link common channel, by multiplying the received power control commands by a spreading sequence;

a position selector for generating a position select signal;

a power control command detector for receiving the despread power control commands and detecting the received power control commands according to the position select signal; and

a power gain controller for controlling a transmission power of a reverse link common channel using the detected power control command.

21. The channel receiving device as claimed in claim 20, wherein the position select signal is used to detect a slot on the power control command channel, into which the power control command for the corresponding subscriber channel is inserted.