IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
UP-0549449
(2004-03-12)
|
등록번호 |
US-7672392
(2010-04-21)
|
우선권정보 |
SE-0300695(2003-03-14) |
국제출원번호 |
PCT/SE2004/000363
(2004-03-12)
|
§371/§102 date |
20060719
(20060719)
|
국제공개번호 |
WO04/082230
(2004-09-23)
|
발명자
/ 주소 |
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
2 인용 특허 :
7 |
초록
▼
Methods, computer-readable medium, a transmitter, a receiver and a transceiver include the transmitter and the receiver in a digital communication system for reducing the transmit power level when there is no user data is to send, i.e., when dummy data is sent instead. That is achieved by defining a
Methods, computer-readable medium, a transmitter, a receiver and a transceiver include the transmitter and the receiver in a digital communication system for reducing the transmit power level when there is no user data is to send, i.e., when dummy data is sent instead. That is achieved by defining a symbol alphabet Q and scrambling a modulated bit stream including user data and dummy data with randomly generated symbols from the symbol alphabet Q.
대표청구항
▼
The invention claimed is: 1. A method in a digital communication system for transmitting a modulated bit stream comprising modulated user data and modulated dummy data, wherein the modulated user data is represented by symbols from a symbol alphabet M, the modulated dummy data is represented by a s
The invention claimed is: 1. A method in a digital communication system for transmitting a modulated bit stream comprising modulated user data and modulated dummy data, wherein the modulated user data is represented by symbols from a symbol alphabet M, the modulated dummy data is represented by a symbol m0, comprising: (a)—generating (601a) symbols q0, . . ,qj randomly from a predefined symbol alphabet Q being a subset of the symbol alphabet M, (b)—scrambling (602a) the modulated bit stream by performing bitwise modulo-2 addition between the modulated bit stream and the randomly generated symbols q0, . . ,qj from Q, and (c)—transmitting (603a) said scrambled modulated bit stream, wherein the predefined symbol alphabet Q is defined so that the transmit power level of the dummy data is substantially lower than the transmit power level of the user data. 2. The method in a digital communication system for receiving a modulated bit stream wherein the modulated bit stream is transmitted and scrambled in accordance with claim 1, the method comprising the steps of: (d)—generating (601b) symbols q0, . . ,qj randomly from the symbol alphabet Q in synchronisation with the transmitter of the received modulated bit stream, and (e)—scrambling (602b) the received modulated bit stream in order to recreate estimated message symbols from symbol alphabet M by performing bitwise modulo-2 addition between the received modulated bit stream and the randomly generated symbols q0, . . ,qj from Q. 3. The method according to claim 1, wherein the modulated bit stream is modulated with Quadrature Amplitude Modulation (QAM). 4. The method according to claim 3, wherein the QAM is 16-QAM. 5. The method according to claim 1, wherein Q comprises four message points {q0, q1, q2, q3} representing signal vectors {s0, s1, s2, s3}, wherein the length of all of the signal vectors is equal, ∥s0∥=∥s1∥=∥s2∥=∥s3∥ and the angle increments from s0 to s1, s1 to s2, s2 to s3 and s3 to s0 are 90 degrees. 6. The method according to claim 5, wherein Q comprises the four innermost message points of the symbol alphabet M. 7. The method according to claim 1, wherein the randomly generated symbols from Q is generated by applying a pseudo-random binary sequence generator to a lookup table wherein the symbol alphabet Q and m0 are stored. 8. The method according to claim 1, wherein the modulated dummy data m0 is consistently represented by zeros or consistently represented by ones. 9. The method according to claim 1, wherein the method is applied on Very high rate Digital Subscriber Line (VDSL). 10. A computer-readable medium directly loadable into the internal memory of a computer within a mobile station or a base station transceiver in a communication system, comprising the software code portions for performing the steps of claim 1. 11. A computer-readable medium comprising a readable program for causing a computer, within a mobile station or a base station transceiver in a communication system, to control an execution of the steps of claim 1. 12. A transmitter (400) in a digital communication system, comprising: means for transmitting a modulated bit stream comprising modulated user data and modulated dummy data, the modulated user data being represented by symbols from a symbol alphabet M, the modulated dummy data being represented by a symbol m0; means (401, 402) for generating symbols q0, . . ,qj randomly from a predefined symbol alphabet Q being a subset of M; means for scrambling the modulated bit stream by performing bitwise modulo-2 addition between the modulated bit stream and the randomly generated symbols q0, . . ,qj from Q; and means for transmitting said scrambled modulated bit stream, wherein the predefined symbol alphabet Q is defined so that a transmit power level of the dummy data is substantially lower than the transmit power level of the user data. 13. A receiver (404) in a digital telecommunication system comprising means for receiving a modulated bit stream wherein the modulated bit stream is transmitted and scrambled by the transmitter in accordance with claim 12, the receiver further comprises means (405,406) for in synchronisation with the transmitter (400) of the received modulated bit stream generating symbols q0, . . ,qj randomly from the symbol alphabet Q, and means for scrambling the received modulated bit stream by performing bitwise modulo-2 addition between the received modulated bit stream and the randomly generated symbols q0, . . ,qj from Q in order to recreate estimated message symbols from symbol alphabet M. 14. The transmitter (400) according to claim 12, wherein the modulated bit stream is modulated with Quadrature Amplitude Modulation (QAM) 15. The transmitter (400) according to claim 14, wherein the QAM is 16-QAM. 16. The transmitter (400) or receiver (404) according to claim 12, wherein Q comprises four message points {q0, q1, q2, q3} representing signal vectors {s0, s1, s2, s3} wherein the length of all of the signal vectors is equal, ∥s0∥=∥s1∥=∥s2∥=∥s3∥ and the angle increments from s0 to s1, s1 to s2, s2 to s3 and s3 to s0 are 90 degrees. 17. The transmitter (400) according to claim 16, wherein Q comprises the four innermost message points of the symbol alphabet M. 18. The transmitter (400) according to claim 12, wherein the randomly generated symbols from Q is generated by applying a pseudo-random binary sequence generator (401;405) to a lookup table (402;406) wherein the symbol alphabet Q and m0 are stored. 19. The transmitter (400) according to claim 12, wherein the modulated dummy data m0 is consistently represented by zeros or consistently represented by ones. 20. The transmitter (400) according to claim 12, wherein the transmitter (400) is applied on Very high rate Digital Subscriber Line (VDSL). 21. A transceiver in a digital communication system that comprises the transmitter according to claim 12. 22. The receiver according to claim 13, wherein the modulated bit stream is modulated with Quadrature Amplitude Modulation (QAM). 23. The receiver according to claim 22, wherein the QAM is 16-QAM. 24. The receiver according to claim 13, , wherein Q comprises four message points {q0, q1, q2, q3} representing signal vectors {s0, s1, s2, s3}, wherein the length of all of the signal vectors is equal, ∥s0∥=∥s1∥=∥s2∥=∥s3∥ and the angle increments from s0 to s1, s1 to s2, s2 to s3 and s3 to s0 are 90 degrees. 25. The receiver according to claim 24, wherein Q comprises the four innermost message points of the symbol alphabet M. 26. The receiver according to claim 13, wherein the randomly generated symbols from Q is generated by applying a pseudo-random binary sequence generator (401;405) to a lookup table (402;406) wherein the symbol alphabet Q and m0 are stored. 27. The receiver according to claim 13, wherein the modulated dummy data m0 is consistently represented by zeros or consistently represented by ones. 28. The receiver according to claim 13, wherein the transmitter (400) or receiver (404) is applied on Very high rate Digital Subscriber Line (VDSL). 29. A transceiver in a digital communication system, comprising the receiver according to claim 13.
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