Apparatus and method of controlling forward link power when in discontinuous transmission mode in a mobile communication system

• US 7,283,836 B2
• Filed: 09/29/2003
• Issued: 10/16/2007
• Est. Priority Date: 06/28/1999
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Jin-Soo, Moon, Hi-Chan, Kim, Jong-Han, Hwang, Jong-Yoon
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US10/673,532
• Publication Number:
  US 20040087331A1
• Time in Patent Office: 1,478 Days
• Field of Search: 455/522, 455/436, 455/517, 455/438, 370/317, 370/318, 370/310
• US Class Current: 455/522
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 1/201 Frame classification, e.g. bad, good or erased frame indication per se H04L1/0082
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/282 taking into account the speed of the mobile
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/288 taking into account the usage mode, e.g. hands-free, data transmission, telephone
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure

Abstract

An apparatus and method of detecting whether data exists in a received signal while a mobile communication terminal is in discontinuous transmission mode. The apparatus and method comprises generating and transmitting a forward power control command for providing the forward power control, and performing forward power control in a mobile communication system. According to the forward power control method, a power control command is generated based on a received frame including a plurality of slots each of which includes power control bits. The ratio of the power control bit energy to noise energy, which is given by a ratio of the accumulated energy of the power control bits in the slots of the received frame to an accumulated energy value of noise in the slots of the received frame, is provided, and the power control command based on a ratio of the accumulated energy value of traffic symbol bits in the slots to the accumulated energy value of the power control bits is generated when the provided ratio of the power control bits to noise is acceptable.

Claims

1. A method of controlling forward link transmission power in a mobile communication system, where a mobile terminal generates a power control command based on a received frame, said received frame including a plurality of slots, each of said plurality of slots including power control bits and non-power control bits the method comprising the steps of:

providing a first ratio of a power of the non-power control bits to a power of the power control bits;

comparing the ratio to a threshold to determine the state of the signal; and

generating a power control command bit based on the comparison.

2. The method as claimed in claim 1, further comprising the steps of:

detecting cyclic redundancy check (CRC) information if the frame includes the CRC information;

performing a cyclic redundancy check (CRC) on the frame using the detected CRC information; and

generating the power control command for reducing the forward link transmission power if the CRC check indicates no errors in the frame.

3. The method as claimed in claim 2, further comprising the step of:

generating the power control command for increasing the forward link transmission power if the CRC check indicates errors in the frame.

4. A method of controlling forward link transmission power in a mobile communication system, where a mobile station generates a power control command based on a received frame, said received frame including cyclic redundancy check (CRC) bits and a plurality of slots, each of said plurality of slots including power control bits and traffic symbol bits, the method comprising the steps of:

detecting the CRC bits of a frame and generating a power control decrease command if the CRC bits are detected;

if the CRC bits are not detected, comparing a control-to-noise ratio to a threshold, said control-to-noise ratio being a ratio of an accumulated power value of the power control bits in the slots of said frame to an accumulated power value of noise in the slots of said frame;

generating, if the control-to-noise ratio is less than the threshold, a forward link power control increase command;

determining, if the control-to-noise ratio is greater than the threshold, whether traffic symbol bits exist in slots of the frame based on a traffic-to-control ratio, said traffic-to-control ratio being a ratio of an accumulated power value of the traffic symbol bits in the slots to the accumulated power value of the power control bits;

generating, if it is determined that traffic symbol bits do not exist, a forward link power control decrease command; and

generating, if it is determined that traffic symbol bits exist, the forward link power control increase command.

5. A forward power control method for performing forward link transmission power control using a power control command received from a terminal in a mobile communication system capable of discontinuous transmission mode, the method comprising:

a first step of transmitting power control bits for power control decrease if a channel state signal of “

sufficient”

is received from the terminal, a “

sufficient”

channel state signal comprises;

(a) a channel state signal having no errors based on a cyclic redundancy check (CRC), or

(b) a channel state signal having errors based on a CRC, having a power control bit power greater than a first threshold, and having a control-to-noise ratio less than a second threshold; and

a second step of transmitting power control bits for power control increase if a channel state signal of “

insufficient”

is received from the terminal, an “

insufficient”

channel state signal comprises a channel state signal having errors based on a CRC, and further comprises;

(a) a power control bit power less than a first threshold, or

(b) a power control bit power greater than a first threshold and having a control-to-noise ratio greater than a second threshold.

6. A forward power control method for performing forward link transmission power control using a power control command received from a terminal in a mobile communication system capable of discontinuous transmission mode, the method comprising:

a first step of checking whether a previous frame has been transmitted when a power control command is received from the terminal;

a second step of transmitting, if it is determined that the previous frame has been transmitted, power control bits for power decrease if the power control command received from the terminal indicates that data has been received by the terminal with no errors;

a third step of transmitting, if it is determined that the previous frame has been transmitted, power control bits for power increase if the power control command received from the terminal indicates that data has been received by the terminal with errors;

a fourth step of transmitting, if it is determined that the previous frame has not been transmitted, power control bits for power decrease if the power control command received from the terminal indicates that no data has been received by the terminal; and

a fifth step of transmitting, if it is determined that the previous frame has not been transmitted, power control bits for power increase if the power control command received from the terminal indicates that data has been received by the terminal.

7. An apparatus for controlling a forward link transmission power in a mobile communication system, where a terminal generates a power control command based on a received frame, said received frame including a plurality of slots, each of said plurality of slots including power control bits, the apparatus comprising:

a calculator for calculating a control-to-noise ratio, said control-to-noise ratio being a ratio of an accumulated power value of power control bits in the slots of a received frame to an accumulated power value of noise in the slots of the received frame; and

a control section for generating a power control command based on a traffic-to-control ratio when the calculated control-to-noise ratio is greater than a threshold, said traffic-to-control ratio being a ratio of an accumulated power value of traffic symbol bits in the slots of the received frame to the accumulated power value of the power control bits.

8. An apparatus for detecting whether received data exists while in discontinuous transmission mode, the apparatus comprising:

a location detector for detecting a location of power of power control bits and a location of power of non-power control bits of a received signal;

a first power measuring device for measuring power of a signal corresponding to the location of the non-power control bits outputted from the location detector and for outputting said measurement;

a second power measuring device for measuring power of a signal corresponding to the location of the power control bits outputted from the location detector and for outputting said measurement; and

a control section for determining whether data exists in the received signal by calculating a ratio of the output of the first power measuring device to the output of the second power measuring device and comparing the ratio to a threshold.

9. The apparatus as claimed in claim 8, further comprising:

a decoder for performing a cyclic redundancy check (CRC) when the transmitted data includes CRC information, wherein the control section determines whether or not the data exists with a value of the CRC state.

10. The apparatus as claimed in claim 8, wherein the control section comprises:

a power ratio calculator for calculating a ratio of the measured power value output of the first power measuring device to a measured power value output of the second power measuring device and for outputting said measured power ratio;

a first comparator for comparing the output measured power ratio of the power ratio calculator with a predetermined threshold value, said predetermined threshold value determined according to the existence or nonexistence of data; and

a controller for detecting whether data exists in the received signal according to the output of the first comparator.

11. The apparatus as claimed in claim 10, wherein the control section further comprises:

a decoder for performing a cyclic redundancy check (CRC) if CRC information is included in the received data;

wherein the controller detects whether data exists in the received signal according to an output of the decoder and the output of the first comparator.

12. The apparatus as claimed in claim 11, wherein the control section further comprises:

a second comparator for comparing, if data exists, an accumulated power value of the power control bits with a minimum threshold value;

wherein the control section detects whether data exists in the received signal according to the CRC state value, the output of the first comparator, and an output of the second comparator.

13. An apparatus for detecting whether data exists in a received signal when in discontinuous transmission mode, and for transmitting a result of detection as a power control command, the apparatus comprising:

a location detector for detecting a location of power of power control bits and a location of power of non-power control bits of the received data;

a first power measuring device for measuring power of a signal corresponding to the location of the non-power control bits outputted from the location detector and for outputting said measure;

a second power measuring device for measuring power of a signal corresponding to the location of the power control bits outputted from the location detector and for outputting said measure; and

a control section for determining whether data exists in the received signal by calculating a ratio of the output of the first power measuring device to the output of the second power measuring device, for comparing the ratio to a threshold, and for generating a power control command based on the comparison; and

a transmitter for transmitting the power control command.

14. The apparatus as claimed in claim 13, further comprising:

a decoder for performing a cyclic redundancy check (CRC) when the transmitted data includes CRC information;

wherein the control section determines whether data exists in the received signal using a value of the CRC state.

15. The apparatus as claimed in claim 13, wherein the control section comprises:

a power ratio calculator for calculating a ratio of the measured power value output of the first power measuring device to a measured power value output of the second power measuring device and for outputting said measured power ratio;

a first comparator for comparing the output measured power ratio of the power ratio calculator with a predetermined threshold value, said predetermined threshold value determined according to the existence or nonexistence of data; and

a controller for detecting whether data exists in the received signal according to the output of the first comparator.

16. The apparatus as claimed in claim 15, wherein the control section further comprises:

a decoder for performing a cyclic redundancy check (CRC) if CRC information is included in the received data;

wherein the controller detects whether data exists in the received signal according to an output of the decoder and the output of the first comparator.

17. The apparatus as claimed in claim 16, wherein the control section further comprises:

a second comparator for comparing, if data exists, an accumulated power value of the power control bits with a minimum threshold value;

wherein the control section detects whether data exists in the received signal according to the CRC state value, the output of the first comparator, and an output of the second comparator.

18. An apparatus for controlling forward link transmission power according to a power control command included in data received while in a discontinuous transmission mode, the apparatus comprising:

a power control command demodulator for demodulating the power control command from the received data to provide the power control command;

a controller for combining the demodulated power control command and information representing whether a previous frame has been transmitted; and

a forward transmitter for transmitting data and power control bits,

wherein the power control command represents one of states of “

sufficient” and

“

insufficient”

, the power control bits for performing a power decrease are generated if the power control command represents the “

sufficient”

state, and the power control bits for performing a power increase are generated if the power control command represents the “

insufficient”

state,

wherein a “

sufficient”

channel state signal comprises;

(a) a channel state signal having no errors based on a cyclic redundancy check (CRC), or

(b) a channel state signal having errors based on a CRC, having a power control bit power greater than a first threshold, and having a control-to-noise ratio less than a second threshold; and

wherein an “

insufficient”

channel state signal comprises a channel state signal having errors based on a CRC, and further comprises;

(a) a power control bit power less than a first threshold, or

(b) a power control bit power greater than a first threshold and having a control-to-noise ratio greater than a second threshold.

19. An apparatus for controlling forward link transmission power according to a power control command included in data received while in a discontinuous transmission mode, the apparatus comprising:

a power control command demodulator for demodulating the power control command from the received data to provide the power control command;

a controller for combining the demodulated power control command and information representing whether a previous frame has been transmitted; and

a forward transmitter for transmitting data and power control bits;

wherein the power control bits are generated and output for performing a power decrease if the previous frame has been transmitted and the power control command represents that the previous frame was received without errors, and the power control bits are generated and output for performing a power decrease if the previous frame has not been transmitted and the power control command represents that the previous frame was received with errors, that power of previous power control bits is greater than a first threshold, and a control-to-noise ratio is less than a second threshold.