Method and apparatus for equalization in transmit and receive levels in a broadband transceiver system

• US 20020090915A1
• Filed: 01/05/2001
• Published: 07/11/2002
• Est. Priority Date: 01/10/2000
• Status: Active Grant

• Current Assignee: Rateze Remote Mgmt. L.L.C. (Intellectual Ventures LLC)
• Original Assignee: AirNet Communications Corporation (Tecore Incorporated)
• Inventors: Noll, John R., Schmutz, Thomas R., Komara, Michael A.
• Granted Patent: US 7,047,042 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04B 1/00 Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/0007 wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels

Abstract

A method (100) for amplitude equalization in transmit and receive levels in a base station wideband transceiver (50) includes the step of assigning (102) a plurality of transmit and receive carrier frequencies to the base station wideband transceiver and the step of flattening (104) the power in the plurality of transmit and receive carrier frequencies in the plurality of base wideband transceivers using software amplitude pre-distortion.

Claims

1. In a base station wideband transceiver capable of operating in a wireless cellular communications system that communicates with mobile subscribers, a method for equalization in transmit and receive levels, comprising the steps of:

assigning a plurality of transmit and receive carrier frequencies to the base station wideband transceiver; and

flattening the power in the plurality of transmit and receive carrier frequencies in the base station wideband transceiver using software amplitude pre-distortion.

2. The method according to claim 1, wherein the step of flattening further comprises the step of discretely flattening the power in each of the plurality of transmit and receive carrier frequencies to provide one nominal output level for a predetermined input level for each transmitted or received RF carrier.

3. The method according to claim 1, wherein the step of flattening using software amplitude pre-distortion further comprises the step of applying a series of flattening coefficients to the receive and transmit signals to compensate for at least the effects of a digital-to-analog converter in the base station wideband transceiver.

4. The method according to claim 1, wherein the step of flattening using software amplitude pre-distortion further comprises the step of compensating for narrowband IF ripple and filter roll-off distortion.

5. The method according to claim 4, wherein the step of flattening using software amplitude pre-distortion further comprises the step of compensating for wideband RF ripple and filter roll-off distortion.

6. The method of claim 1, wherein the method further comprises the step of making narrowband IF channel measurements using an automated broadband radio frequency transceiver test (ABRFTT) to determine a set of coefficients for each narrowband IF channel.

7. The method of claim 6, wherein the ABRFTT further comprises the step of making wideband RF channel measurements that step through the wideband bandwidth to determine a set of coefficients for the wideband RF channel.

8. The method of claim 7 wherein the ABRFTT creates 25 narrowband coefficients for a 5 MHz IF bandwidth and 300 wideband coefficients for a 60 MHz RF bandwidth having 200 kHz channels.

9. The method of claim 7, wherein the method further comprises the step of storing the coefficients in a memory in the base station wideband transceiver enabling the interchangeability of base station wideband transceivers within the wireless cellular communication system.

10. The method of claim 9, wherein the method further comprises the steps of storing the wideband coefficients and the narrowband coefficients in a look-up table in memory within the base station wideband transceiver.

11. The method of claim 7, wherein the method further comprises the step of setting a corresponding gain for each individual radio frequency based on the narrowband IF and wideband RF coefficients determined from the automated broadband radio transceiver test.

13. The broadband radio frequency base station transceiver of claim 12, wherein the receiver has a receiver digital signal processor that applies a series of flattening coefficients to the receive signal to compensate for the effects of the wideband RF and narrowband IF ripple and filter roll-off distortion.

14. The broadband radio frequency base transceiver of claim 12, wherein the transmitter has a transmitter digital signal processor that applies a series of flattening coefficients to compensate for the effects of the digital-to-analog converter.

15. The broadband radio frequency base transceiver of claim 12, wherein the transceiver further comprises a transceiver microprocessor module having memory for storing a plurality of wideband RF and narrowband IF coefficients for setting a corresponding gain for each individual frequency.

16. The broadband radio frequency base transceiver of claim 12, wherein the transceiver is a translating repeater.

18. The wireless communication system of claim 17, wherein each of the plurality of wideband base transceivers is a translating repeater.

12. A broadband radio frequency base transceiver capable of receiving and transmitting simultaneously on multiple frequencies, comprising:

a receiver coupled to an plurality of analog-to-digital converters, wherein the analog-to-digital converters provide a plurality of digitized signals;

a transmitter coupled to a digital-to-analog converter, wherein the digital-to-analog converter produces an analog signal from a multi-channel digital combiner; and

at least one digital signal processor programmed to discretely flatten the power in each of the plurality of transmit and receive carrier frequencies using software amplitude pre-distortion.

17. A wireless cellular communications system with improved equalization in transmit and receive levels, comprises:

a plurality of wideband transceivers communicating with mobile subscribers, wherein a plurality of transmit and receive carrier radio frequencies are assigned to the plurality of wideband transceivers, each of the wideband transceivers comprises;

a receiver coupled to an plurality of analog-to-digital converters, wherein the analog-to-digital converters provide a plurality of digitized signals to a corresponding plurality of digital channelizers;

a transmitter coupled to a digital-to-analog converter, wherein the digital-to-analog converter receives an analog signal from a multi-channel digital combiner;

a first digital signal processor programmed to discretely flatten the power in each of the plurality of receive carrier frequencies using software amplitude pre-distortion; and

a second digital signal processor programmed to discretely flatten the power in each of the plurality of transmit carrier frequencies using software amplitude pre-distortion.