Versatile system for signal shaping in ultra-wideband communications

• US 20050232336A1
• Filed: 04/19/2005
• Published: 10/20/2005
• Est. Priority Date: 04/20/2004
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Batra, Anuj, Balakrishnan, Jaiganesh, Lingam, Srinivas
• Application Number:
  US11/109,334
• Publication Number:
  US 20050232336A1
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

The present invention provides a versatile system for selectively altering or shaping transmission signals in an ultra-wideband communications system (100). The system provides a serial to parallel conversion function (102) with a serial data input (116). The serial to parallel conversion function converts the serial data and outputs it in parallel format. An adjustment function (104) receives the now parallel data and selectively alters the parallel data responsive to some code or vector (118). A frequency-to-time-domain conversion function (106) receives the selectively altered parallel data and transmits it to a parallel-to-serial conversion function 108. The now serial data transfer through an OFDM prefix/suffix function 110 and a digital-to-analog conversion function 112, to an up conversion mixer function 114. Encoded digital data bits are input, converted to parallel format, and passed to the spectrum adjustment function, which provides selective adjustment of specific data units (i.e., specific OFDM sub-carriers or tones).

Claims

1. An ultra-wideband wireless communications system comprising:

a serial data input;

a serial to parallel conversion function, adapted to receive serial data from the serial data input and to output parallel data;

an adjustment function, adapted to receive parallel data from the serial to parallel conversion function and to selectively alter the parallel data; and

a frequency-to-time-domain conversion function, adapted to receive selectively altered parallel data from the adjustment function and to prepare the selectively altered parallel data for transmission over a wireless channel.

2. The system of claim 1, wherein the ultra-wideband wireless communications system comprises a multi-band orthogonal frequency division multiplexing system.

3. The system of claim 1, wherein the ultra-wideband wireless communications system comprises a system operating between 3.1 gigahertz and 10.6 gigahertz.

4. The system of claim 1, wherein the adjustment function comprises one or more multipliers adapted to alter gain of a signal.

5. The system of claim 4, wherein the adjustment function further comprises one or more multipliers adapted to selectively alter gain of a plurality of signal sub-bands, based on a respective plurality of weighting vectors.

6. The system of claim 1, wherein the frequency-to-time-domain conversion function comprises an inverse fast Fourier transform.

7. The system of claim 6, wherein the adjustment function comprises one or more multipliers implemented with the frequency-to-time-domain conversion function.

8. The system of claim 1, wherein the ultra-wideband wireless communications system further comprises a carrier leak-through suppression function.

9. The system of claim 8, wherein the carrier leak-through suppression function further comprises a feedback loop from an up conversion mixer function to the adjustment function.

10. The system of claim 8, wherein the carrier leak-through suppression function is dynamic.

11. A method of transmitting data in a multi-band orthogonal frequency division multiplexing system, the method comprising the steps of:

providing digital data in a serial format;

converting the serial digital data to parallel digital data units;

selectively altering a parallel digital data unit;

converting the selectively altered parallel digital data unit from a frequency domain into a time domain; and

transmitting the selectively altered parallel digital data in a time domain over a wireless channel to a receiver.

12. The method of claim 11, wherein the step of converting the serial digital data to parallel digital data units further comprises converting the serial digital data to an orthogonal frequency division multiplexing sub-carrier.

13. The method of claim 11, wherein the step of selectively altering a parallel digital data unit further comprises selectively increasing the gain of the parallel digital data unit.

14. The method of claim 11, wherein the step of selectively altering a parallel digital data unit further comprises selectively decreasing the gain of the parallel digital data unit.

15. The method of claim 11, wherein the step of selectively altering a parallel digital data unit further comprises selectively altering a parallel digital data unit responsive to a calibration process.

16. A versatile system for altering the transmission signal profile of a multi-band orthogonal frequency division multiplexing system data tone, the system comprising:

a serially input data tone;

a serial to parallel conversion function, that receives serially input data tone and converts it to a parallel data tone;

an adjustment function that receives the parallel data tone and selectively modifies the parallel data tone, responsive to an adjustment vector, to render an adjusted data tone;

a frequency to time domain conversion function that receives the adjusted data tone and prepares converts the adjusted data tone into the time domain; and

a wireless communication channel, across which the adjusted data tone is transmitted in the time domain.

17. The system of claim 16, wherein the adjustment vector is selected to suppress carrier leak-through.

18. The system of claim 16, wherein the adjustment vector is selected to optimize sub-tone transmission power.

19. The system of claim 16, wherein the adjustment vector is selected to nullify a desired sub-tone.

20. The system of claim 16, wherein the adjustment function cooperatively utilizes half-duplex receiver circuitry in a full duplex manner.

21. The system of claim 20, wherein the adjustment function cooperatively utilizes time-domain frequency offset correction circuitry.