IP Library Granted Patent US 9,178,683
Granted Patent B2
US 9,178,683 · App. 13/478,744 · Granted Nov 3, 2015

Method and apparatus for parallel demodulation of high symbol rate data streams in a communications system

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 9,178,683
App. No.
13/478,744
Granted
Nov 3, 2015
Kind
B2
Abstract

A dynamic and flexible architecture and methods for demodulation of high data-rate streams with high symbol-rates, such as in satellite communications systems or computer network communications systems, is provided. A data stream of a data transmission is received, the data stream corresponding to a plurality of data symbols. A plurality of data samples corresponding to each of the data symbols is generated. Further, one or more representative data samples, corresponding each of the data symbols, are generated based at least in part on timing control signals and the generated data samples for the respective data symbol. The generated data samples corresponding to each of the data symbols other than the representative data samples are dropped. The timing control signals are then adjusted based at least in part on the generated representative data samples.

Claims (55)

1. A method comprising:

receiving a data stream of a data transmission, the data stream corresponding to a plurality of data symbols;

generating a plurality of intermediate data samples corresponding to each of the data symbols;

generating one or more representative data samples, corresponding to each of the data symbols, based at least in part on timing control signals and the intermediate data samples for the respective data symbol;

dropping certain of the representative data samples corresponding to each of the data symbols based on drop control signals;

generating error correction signals by determining phase errors corresponding to timing errors in processing the data samples, and filtering the phase errors; and

adjusting the timing control signals and the drop control signals based at least in part on the error correction signals.

2. A method according to claim 1 , wherein the representative data samples comprise one or more of a fractional data sample and an integer data sample, and the timing control signals comprise one or more of a fractional time and an integer time.

3. A method according to claim 1 , wherein the data stream is processed in a parallelized manner.

4. A method according to claim 1 , wherein the data transmission comprises one of a continuous mode or a burst mode data transmission in a communications system, wherein the communications system comprises one or more of a satellite communications system and a computer network communications system.

5. A method according to claim 1 , further comprising demodulating the data stream, wherein the demodulation of the data stream comprises:

formatting the data samples into a parallelized format; and

generating the intermediate data samples at a sampling rate of at least approximately twice the symbol rate of the received data stream; and

wherein the generation of the representative data samples corresponding to each of the data symbols is performed based at least in part on a symbol timing recovery using a clock rate of a slower rate than the symbol rate of the data stream.

6. A method according to claim 5 , wherein the representative data samples comprise one or more of a fractional data sample and an integer data sample, and the timing control signals comprise one or more of a fractional time and an integer time.

7. An apparatus comprising:

at least one processor; and

at least one memory including computer program code for one or more programs,

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,

receive a data stream of a data transmission, the data stream corresponding to a plurality of data symbols;

generate a plurality of intermediate data samples corresponding to each of the data symbols;

generate one or more representative data samples, corresponding to each of the data symbols, based at least in part on timing control signals and the intermediate data samples for the respective data symbol;

drop certain of the representative data samples corresponding to each of the data symbols based on drop control signals;

generate error correction signals by determining phase errors corresponding to timing errors in processing the data samples, and filtering the phase errors; and

adjust the timing control signals and the drop control signals based at least in part on the error correction signals.

8. An apparatus according to claim 7 , wherein the data stream is processed in a parallelized manner.

9. An apparatus according to claim 7 , wherein the data transmission comprises one of a continuous mode or a burst mode data transmission in a communications system, wherein the communications system comprises one or more of a satellite communications system and a computer network communications system.

10. An apparatus according to claim 7 , wherein the apparatus is further caused to demodulate the data stream, wherein the demodulation of the data stream comprises:

formatting the data samples into a parallelized format; and

processing the data samples at a sampling rate of at least approximately twice the symbol rate of the received data stream; and

wherein the generation of the representative data samples corresponding to each of the data symbols is performed based at least in part on a symbol timing recovery using a clock rate of a slower rate than the symbol rate of the data stream.

11. An apparatus comprising:

a receiver module configured to receive a data stream of a data transmission, the data stream corresponding to a plurality of data symbols;

a sampler module configured to generate a plurality of intermediate data samples corresponding to each of the data symbols;

a control module configured to generate timing control signals and drop control signals;

an interpolator module configured to generate one or more representative data samples, corresponding to each of the data symbols, based at least in part on the timing control signals and the intermediate data samples for the respective data symbol;

a sample dropper module configured to drop certain of the representative data samples corresponding to each of the data symbols based on the drop control signals;

a filter configured to filter the representative data samples to provide one or more filtered data samples corresponding to each of the respective data symbols;

a phase detector configured to determine phase information regarding the filtered data samples; and

a loop filter configured to filter the phase information, and to generate filtered phase information signals, wherein the timing control signals and the drop control signals generated by the control module are based at least in part on the filtered phase information signals; and

wherein the control module is further configured to adjust the timing control signals and the drop control signals based on the filtered phase signals.

12. An apparatus according to claim 11 , wherein the control module comprises:

an oscillator configured to generate the timing control signals and the drop control signals, wherein the drop control signals are generated based at least in part on a ratio between an incoming symbol rate and an outgoing sample rate for the data stream.

13. An apparatus according to claim 12 , wherein the representative data samples comprise one or more of a fractional data sample and an integer data sample, and the timing control signals comprise one or more of a fractional time and an integer time.

14. An apparatus according to claim 12 , wherein the data transmission comprises one of a continuous mode or a burst mode data transmission in a communications system, wherein the communications system comprises one or more of a satellite communications system and a computer network communications system.

15. An apparatus according to claim 12 , wherein

the oscillator comprises a numerically controlled oscillator (NCO),

the interpolator module comprises one or more Lagrange interpolators;

the sample dropper module comprises one or more shift registers configured to provide the determined optimal representative data samples as output data samples for further processing,

the filter comprises a finite impulse response (FIR) matched filter, and

the loop filter runs at a rate of (symbol rate/N), where the “symbol rate” corresponds to the symbol rate for the received data stream and “N” corresponds to a number of the data symbols.

16. An apparatus according to claim 15 , wherein the interpolator module determines the representative data samples corresponding to each of the data symbols through an interpolation operation based at least in part on two or more of the data samples for the respective data symbol and the timing control signals.

17. An apparatus according to claim 11 , wherein the interpolator module determines the representative data samples corresponding to each of the data symbols through an interpolation operation based at least in part on two or more of the data samples for the respective data symbol and the timing control signals.

18. An apparatus according to claim 11 , wherein the receiver module is further configured to format the received data symbols into a parallelized format.

19. An apparatus according to claim 18 , wherein the data stream is processed at a sampling rate of at least approximately twice the symbol rate of the data stream, and generation of the representative data samples is performed based at least in part on a symbol timing recovery using a clock rate of a slower rate than the symbol rate of the data stream.

Assignments (4)
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE APPLICATION NUMBER 15649418 PREVIOUSLY RECORDED ON REEL 050600 FRAME 0314. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT OF PATENT SECURITY AGREEMENTS. Recorded Sep 3, 2020
From: WELLS FARGO, NATIONAL BANK ASSOCIATION
To: U.S. BANK NATIONAL ASSOCIATION
Reel/Frame 053703/0367 →
ASSIGNMENT OF PATENT SECURITY AGREEMENTS Recorded Oct 1, 2019
From: WELLS FARGO BANK, NATIONAL ASSOCIATION
To: U.S. BANK NATIONAL ASSOCIATION
Reel/Frame 050600/0314 →
SECURITY INTEREST Recorded Mar 11, 2014
From: HUGHES NETWORK SYSTEMS LLC
To: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 032404/0094 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 23, 2012
From: VARMA, KRISHNARAJ; HUANG, TONY; WU, XIAOMING
To: HUGHES NETWORK SYSTEMS, LLC
Reel/Frame 028258/0047 →