Device and method for controlling powers of orthogonal channel and quasi-orthogonal channel in CDMA communication system

• US 6,671,266 B1
• Filed: 03/26/1999
• Issued: 12/30/2003
• Est. Priority Date: 03/26/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yoon, Soon-Young, Moon, Hi-Chan, Ahn, Jae-Min, Yeom, Jae-Heung
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Yun, Eugene
• Application Number:
  US09/277,653
• Time in Patent Office: 1,740 Days
• Field of Search: 370/320, 370/335, 370/342, 370/318, 370/336, 370/203, 370/206, 370/208, 370/209, 455/69, 455/522
• US Class Current: 370/342
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission

Abstract

A power control device for a CDMA communication system using different kinds of spreading codes. In the power control device for a base station device, a first channel generator generates a first channel signal by spreading first input data with an orthogonal code and a second channel generator generates a second channel signal by spreading second input data with a quasi-orthogonal code. The second channel signal has a gain higher than that of the first channel signal. A first gain controller controls power of the first channel signal and a second gain controller controls power of the second channel signal. An adder adds the first channel signal to the second channel signal, and a spreader spreads a signal output from the adder with a pseudo-random noise (PN) code. The base station transmits a response request message to a mobile station via the second channel, and retransmits the response request message after increasing a transmission power of the second channel when a response message is not received from the mobile station.

Claims

1. A base station device for a code division multiple access (CDMA) communication system, comprising:

a first channel generator for generating a first channel signal by spreading first input data with an orthogonal code;

a second channel generator for generating a second channel signal by spreading second input data with a quasi-orthogonal code, said second channel signal having a gain higher than that of the first channel signal;

a first gain controller for controlling power of the first channel signal;

a second gain controller for controlling power of the second channel signal;

an adder for adding the first channel signal to the second channel signal; and

a spreader for spreading a signal output from the adder with a pseudo-random noise (PN) code.

2. The base station device as claimed in claim 1, wherein each of the channel generators comprises:

a channel encoder for encoding the input data;

an interleaver for interleaving an output of the channel encoder; and

a multiplier for multiplying an output of the interleaver by a corresponding spreading code.

3. The base station device as claimed in claim 1, further comprising a controller for controlling powers of the first and second gain controllers.

4. The base station device as claimed in claim 3, wherein the controller controls the power of the first channel in response to a power control command for the first channel received from a mobile station, and controls the power of the second channel in response to a power control command for the second channel received from the mobile station.

5. The base station device as claimed in claim 3, wherein the controller sets a power ratio between the first channel spread with the orthogonal code and the second channel spread with the quasi-orthogonal code according to a power ratio change command received from a mobile station.

6. The base station device as claimed in claim 3, wherein transmission powers of the first and second channels are controlled according to a fast power control command for the first channel and a power ratio change command message received from a mobile station.

7. The base station device as claimed in claim 6, wherein the power ratio change command is varied according to a signal-to-interference ratio (SIR) for the second channel in the mobile station.

8. The base station device as claimed in claim 6, wherein the power ratio change command is generated according to a signal-to-interference (SIR) ratio between the first channel spread with the orthogonal code and the second channel spread with the quasi-orthogonal code.

9. The base station device as claimed in claim 6, wherein the power ratio is re-set by controlling the power of the second channel spread with the quasi-orthogonal code.

10. The base station device as claimed in claim 6, wherein the power ratio change command is transmitted via a reverse link control channel.

11. The base station device as claimed in claim 6, wherein a time required for accumulating an SIR of the second channel is longer than a time required for accumulating an SIR of the first channel, at the mobile station.

12. The base station device as claimed in claim 1, wherein the base station transmits a response request message to a mobile station via the second channel, to retransmit the response request message after increasing a transmission power of the second channel when a response message is not received from the mobile station.

13. The base station device as claimed in claim 1, wherein the base station sends a response message at a pre-set power level via the second channel, upon receiving a response request message from a mobile station.

14. A mobile station device for a CDMA communication system, comprising:

a first controller for generating a power control command by averaging an SIR of a first channel signal despread with an orthogonal code for a first time and comparing the averaged SIR with a threshold value;

a second measurer for averaging an SIR of a second channel despread with a quasi-orthogonal code for a second time longer than the first time; and

a message generator for generating a power ratio change command responsive to the SIR of the first channel signal and the SIR of the second channel.

15. The mobile station device as claimed in claim 14, wherein the first controller comprises:

a first measurer for measuring the SIR of the first channel signal;

a first comparator for comparing the measured SIR with a threshold value; and

a power control command generator for generating the power control command according to an output of the first comparator.

16. The mobile station device as claimed in claim 14, wherein the message generator comprises:

a second comparator for comparing the SIR of the second channel signal with first and second threshold values; and

a power ratio change command generator for generating the power ratio change command for decreasing a transmission power of the second channel signal when the SIR is higher than the first threshold value and increasing the transmission power of the second channel signal when the SIR is lower than the second threshold value.

17. The mobile station device as claimed in claim 14, wherein the message generator compares the SIR of the first channel signal with the SIR of the second channel signal and generates the power ratio change command for controlling a power ratio between the first and second channel signals according to the comparison result.

18. The mobile station device as claimed in claim 14, wherein the mobile station sends a response request message to a base-station and the base station then sends a response message via the second channel upon receiving the response request message.

19. The mobile station device as claimed in claim 18, wherein the base station determines whether the same response request message has been received repeatedly within a predefined time, and increases the transmission power of the second channel when the same response request message has been received repeatedly.

20. The mobile station device as claimed in claim 14, further comprising a decoder for decoding the second channel signal.

21. The mobile station device as claimed in claim 20, wherein the power ratio change command is generated according to errors generated during decoding at the decoder.

22. The mobile station device as claimed in claim 14, wherein the first channel despread with the orthogonal code is a fundamental channel and the second channel despread with the quasi-orthogonal code is a dedicated control channel.

23. A power control method in a base station for a CDMA communication system, comprising:

generating a first channel signal by spreading first input data with an orthogonal code;

generating a second channel signal by spreading second input data with a quasi-orthogonal code;

controlling power of the first channel signal;

controlling power of the second channel signal, said second channel signal having a gain higher than that of the first channel signal;

adding the first channel signal to the second channel signal; and

spreading the added signal with a PN code.

24. The power control method in a base station device as claimed in claim 23, wherein each of the first and second channel generation steps comprises the steps of:

encoding the input data;

interleaving the encoded data; and

multiplying the interleaved data by a corresponding spreading code.

25. The power control method in a base station device as claimed in claim 24, wherein the power control steps control power of the first channel in response to a power control command for the first channel received from a mobile station, and control power of the second channel in response to a power control command for the second channel received from the mobile station.

26. The power control method in a base station device as claimed in claim 24, wherein the power control steps set a power ratio between the first and second channels according to a power ratio change command received from a mobile station.

27. The power control method in a base station device as claimed in claim 24, wherein transmission powers of the first and second channels are controlled according to a fast power control command for the first channel and a power ratio change command, received from a mobile station.

28. The power control method in a base station device as claimed in claim 27, wherein the power ratio change command is varied according to a signal-to-interference ratio (SIR) for the second channel in the mobile station.

29. The power control method in a base station device as claimed in claim 28, wherein the power ratio change command is generated according to a signal-to-interference ratio (SIR) between the first channel spread with the orthogonal code and the second channel spread with the quasi-orthogonal code.

30. The power control method in a base station device as claimed in claim 28, wherein the power ratio is re-set by controlling the power of the second channel spread with the quasi-orthogonal code.

31. The power control method in a base station device as claimed in claim 28, wherein the power ratio change command is transmitted via a reverse link control channel.

32. The power control method in a base station device as claimed in claim 28, wherein a time required for accumulating an SIR of the second channel is longer than a time required for accumulating an SIR of the first channel, at the mobile station.

33. The power control method in a base station device as claimed in claim 23, wherein the base station transmits a response request message to a mobile station via the second channel, to retransmit the response request message after increasing a transmission power of the second channel when a response message is not received from the mobile station.

34. The power control method in a base station device as claimed in claim 23, wherein the base station sends a response message at a pre-set power level via the second channel, upon receiving a response request message from a mobile station.

35. A power control method in a mobile station device for a CDMA communication system, comprising:

generating a power control command by averaging an SIR of a first channel signal despread with an orthogonal code for a first time and comparing the averaged SIR with a threshold value;

averaging an SIR of a second channel despread with a quasi-orthogonal code for a second time longer than the first time; and

generating a power ratio change command being set such that the SIR of the first channel signal is identical to the SIR of the second channel.

36. The power control method in a mobile station device as claimed in claim 35, wherein the power control command generation step comprises the steps of:

measuring the SIR of the first channel signal;

comparing the measured SIR with a threshold value; and

generating a power control message responsive to said SIR of a first channel and second channel.

37. The power control method in a mobile station device as claimed in claim 35, wherein the power control message generation step comprises the steps of:

comparing the SIR of the second channel signal with first and second threshold values; and

generating the power ratio change command for decreasing a transmission power of the second channel signal when the SIR is higher than the first threshold value and increasing the transmission power of the second channel signal when the SIR is lower than the second threshold value.

38. The power control method in a mobile station device as claimed in claim 35, wherein the power control message generation step compares the SIR of the first channel signal with the SIR of the second channel signal and generates the power ratio change command for controlling a power ratio between the first and second channel signals according to the comparison result.

39. The power control method in a mobile station device as claimed in claim 35, wherein the mobile station sends a response request message to a base station via a reverse control channel and the base station then sends a response message via the second channel upon receiving the response request message.

40. The power control method in a mobile station device as claimed in claim 39, wherein the base station determines whether the same response request message has been received repeatedly within a predefined time, and increases the transmission power of the second channel.

41. The power control method in a mobile station device as claimed in claim 35, further comprising the step of decoding the second channel signal.

42. The power control method in a mobile station device as claimed in claim 41, wherein the power ratio change command is generated according to errors generated during decoding at the decoder.

43. The power control method in a mobile station device as claimed in claim 35, wherein the first channel despread with the orthogonal code is a supplemental channel and the second channel despread with the quasi-orthogonal code is a dedicated control channel.