ADSL transceiver implemented with associated bit and energy loading integrated circuit

• US 6,084,906 A
• Filed: 12/17/1997
• Issued: 07/04/2000
• Est. Priority Date: 12/17/1997
• Status: Expired due to Term

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Integrated Telecom Express, Inc.
• Inventors: Liu, Ming-Kang, Chen, Chunta, Kao, Chiihsin
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): GHAYOUR, MOHAMMAD H
• Application Number:
  US08/991,998
• Time in Patent Office: 930 Days
• Field of Search: 375/260, 375/295, 375/219, 375/222, 375/225, 375/220, 379/93.08, 370/235, 370/231
• US Class Current: 375/220
• CPC Class Codes: H04L 5/0044 allocation of payload

Abstract

An ADSL transceiver includes a new circuit and various iterative initialization and fine tuning routines for optimizing the bit and energy configurations of data sub-channels in a multi-channel data transmission signal. The routines quickly converge to a target data rate by first estimating a power margin, and generating a bounded interval that includes the target rate. Thereafter, a binary iterative portion of the routine takes over and effectuates a final convergence to the target rate. A new mechanism for determining useful sub-channels is also disclosed. The resulting routines are extremely useful in that they maximize a data rate for a given power margin, and conversely, maximize a power margin for a given data rate. Two variants of a fine tuning process are also disclosed, and both can be used in combination to maximize system performance. The circuits and routines are preferably implemented in the form of an integrated circuit or module that includes a digital signal processor (DSP) and associated memory running a permanent binary coded executable routine for analyzing sub-channel signal-to-noise characteristics, determining theoretical bit capacity loadings, evaluating power performance margins, and optimizing sub-channel configurations based on a series of iterative calculations intended to maximize the overall system power performance margin for any given target data rate. In an alternative form, the DSP may include a RAM that is loaded with the initialization and fine tuning routines from a computer readable media such as a floppy disk, a hard disk, a magnetic tape, a CD-ROM or other non-volatile computer readable storage media. In another embodiment, the circuits and routines may be implemented in the form of a software modem operating directly on a user'"'"'s machine instead of using a separate DSP and associated memory.

Claims

1. An article of manufacture comprising:

a processor accessible storage structure embodied in an integrated circuit; and

a processor executable routine stored in the storage structure, wherein the executable routine includes instructions for causing a processor to operate to configure data and energy loadings of K sub-channels of a high speed data transmission system so that it achieves a data rate R, the instructions including directions to the processor to execute the following operations;

(a) determining K signal-to-noise ratios associated with K sub-channels; and

(b) determining data capacities of each of the K sub-channels based on an evaluation of the following parameters;

i) the K signal-to-noise ratios; and

ii) said data rate R; and

iii) a number N_ch of the K sub-channels having a non-zero bit capacity; and

wherein the data capacities can be determined by the processor executing one or more iterations of the operations of step (b) and N_ch is calculated during each iteration.

2. The article of claim 1, wherein the processor accessible storage structure is a semiconductor memory and the processor executable routine is encoded as binary data bits programmed in the memory.

3. The article of claim 1, wherein the processor executable routine also includes instructions for operations to determine minimum (b_min (i)) and maximum (b_max (i)) bit loadings for each of the sub-channels.

4. The article of claim 3, wherein the processor executable routine also includes instructions for operations to determine N_ch based on an evaluation of b_min (i) and b_max (i).

5. The article of claim 4, wherein the processor executable routine also includes instructions for operations to determine power modification factors e_min (i) and e_max (i) for each of the sub-channels.

6. The article of claim 5, wherein the processor executable routine also includes instructions for operations to determine N_ch based on an evaluation of b_min (i), b_max (i), e_min (i) and e_max (i).

7. The article of claim 1, wherein the processor executable routine also includes instructions for operations to determine the data capacities based on a consideration of maximum transmission power P for such system.

8. The article of claim 1, wherein the processor executable routine also includes instructions for operations to dynamically adapt the system to achieve said data rate R by generating an interval consisting of two different values {B₁, B₂ } which values bound (B₁ <

B<

B₂) a target value B, where B=R/R_symbol, and where R_symbol is a constant.

9. The article of claim 8, wherein the processor executable routine also includes instructions for operations to determine the two different values B₁, B₂ based on an estimated value of a power margin (γ

_m) for said system.

10. The article of claim 9, wherein the processor executable routine also includes instructions for operations to associate a first power margin γ

_min with B₁, and to associate a second power margin γ

_max with B₂, and for achieving said data rate based on computing an iterative power margin γ

_m =√

γ

_min *√

γ

_max.

11. The article of claim 1 wherein the processor executable routine also includes instructions for operations to dynamically adapt the data capacities in response to changes in transmission characteristics or said data rate R.

12. An article of manufacture comprising:

a processor accessible readable media; and

a processor executable routine stored in the media, wherein the executable routine causes a processor to operate to configure data and energy loadings of K sub-channels of a high speed data transmission system so that it achieves a data rate R by performing the following operations;

(a) determining K signal-to-noise ratios associated with K sub-channels; and

(b) determining data capacities of each of the K sub-channels based on an evaluation of the following parameters;

i) the K signal-to-noise ratios; and

ii) said data rate R; and

iii) a number N_ch of the K sub-channels having a non-zero bit capacity; and

wherein the data capacities can be determined by the processor by executing one or more iterations of the operations of step (b) and N_ch is calculated during each iteration.

13. The article of claim 12 wherein the readable media includes any one of a floppy disk, a hard disk, a magnetic tape, a CD-ROM or other non-volatile computer readable storage media.

14. The article of claim 13, wherein the processor executable routine can be transferred from said readable media to a high speed memory of a processor so that such processor can execute the routine.

15. The article of claim 12, wherein the readable media also includes instructions for operations to determine minimum (b_min (i)) and maximum (b_max (i)) bit loadings for each of the sub-channels.

16. The article of claim 15, wherein the readable media also includes instructions for operations to determine N_ch based on an evaluation of b_min (i) and b_max (i).

17. The article of claim 16, wherein the readable media also includes instructions for operations to determine power modification factors e_min (i) and e_max (i) for each of the sub-channels.

18. The article of claim 17, wherein the readable media also includes instructions for operations to determine N_ch based on an evaluation of b_min (i), b_max (i), e_min (i) and e_max (i).

19. The article of claim 12, wherein the readable media also includes instructions for operations to determine the data capacities based on a consideration of maximum transmission power P for such system.

20. The article of claim 12, wherein the readable media also includes instructions for operations to dynamically adapt the system to achieve said data rate R by generating an interval consisting of two different values {B₁, B₂ } which values bound (B₁ <

B<

B₂) a target value B, where B=R/R_symbol, and where R_symbol is a constant.

21. The article of claim 20, wherein the readable media also includes instructions for operations to determine the two different values B₁, B₂ based on an estimated value of a power margin (γ

_m) for said system.

22. The article of claim 21, wherein the readable media also includes instructions for operations to associate a first power margin γ

_min with data rate B₁, and to associate a second power margin γ

_max with data rate B₂, and for achieving said data rate based on computing an iterative power margin γ

_m =√

γ

_min *√

γ

_max.

23. The article of claim 12 wherein the readable media also includes instructions for operations to dynamically adapt the data capacities in response to changes in transmission characteristics or said data rate R.

24. A method of manufacturing an integrated circuit, which circuit is used to configure data capacities of K sub-channels in a high speed transmission system using a data rate R, said method comprising the steps of:

forming a memory storage structure such that it is accessible by a data processing unit;

programming the memory storage structure such that it implements a processor executable routine, the routine including instructions for causing the processor to execute the following operations;

(a) determining K signal-to-noise ratios associated with K sub-channels; and

(b) determining data capacities of each of the K sub-channels based on an evaluation of the following parameters;

i) the K signal-to-noise ratios; and

ii) said data rate R; and

iii) a number N_ch of the K sub-channels having a non-zero bit capacity; and

wherein the data capacities can be determined by the processor by one or more iterations of step (b) and N_ch is calculated during each iteration.

25. The method of claim 24, wherein the step of programming the memory storage structure includes encoding binary data bits therein corresponding to the executable routine.

26. The method of claim 24, wherein the memory storage structure is programmed to also include instructions for operations to determine minimum (b_min (i)) and maximum (b_max (i)) bit loadings for each of the sub-channels.

27. The method of claim 26, wherein the memory storage structure is programmed also to include instructions for operations to determine N_ch based on an evaluation of b_min (i) and b_max (i).

28. The method of claim 27, wherein the memory storage structure is programmed also to include instructions for operations to determine power modification factors e_min (i) and e_max (i) for each of the sub-channels.

29. The method of claim 28, wherein the memory storage structure is also programmed to include instructions for operations to determine N_ch based on an evaluation of b_min (i), b_max (i), e_min (i) and e_max (i).

30. The method of claim 24, wherein the memory storage structure is also programmed to include instructions for operations to determine the data capacities based on a consideration of maximum transmission power P for such system.

31. The method of claim 24, wherein the memory storage structure is also programmed to include instructions for operations to dynamically adapt the system to achieve said data rate R by generating an interval consisting of two different values {B₁, B₂ } which values bound (B₁ <

B<

B₂) a target value B, where B=R/R_symbol, and where R_symbol is a constant.

32. The method of claim 31, wherein the memory storage structure is also programmed to include instructions for operations to determine the two different values B₁, B₂ based on an estimated value of a power margin (γ

_m) for said system.

33. The method of claim 32, wherein the memory storage structure is also programmed to include instructions for operations to associate a first power margin γ

_min with B₁, and to associate a second power margin γ

_max with B₂, and for achieving said data rate based on computing an iterative power margin γ

_m =√

γ

_min *√

γ

_max.

34. The method of claim 24 wherein the memory storage structure is also programmed to include instructions for operations to dynamically adapt the data capacities in response to changes in transmission characteristics or said data rate R.