DIGITALLY CONVERTIBLE RADIO

• US 20070153936A1
• Filed: 03/14/2007
• Published: 07/05/2007
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Da Silveira, Marthinus, McGowan, Neil, Parvan, Mihai, Conrod, Matthew
• Granted Patent: US 7,508,885 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H03F 1/3241 using predistortion circuits H03F1/3211, H03F1/3217 take precedence
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 1/3282 Acting on the phase and the amplitude of the input signal
• CPC Class Codes: H03F 1/34 Negative-feedback-circuit arrangements with or without positive feedback H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence ; for rejection of common mode signals H03F3/45479
• CPC Class Codes: H03F 2200/204 A hybrid coupler being used at the output of an amplifier circuit
• CPC Class Codes: H03F 2200/393 A measuring circuit being coupled to the output of an amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 2001/0433 with linearisation using feedback

Abstract

A forward link transmitter in a sectored cell includes a baseband processor having traditional baseband signal digital processing circuitry in addition to including a digital hybrid matrix (vector and delay compensated transformation module) whose phase and amplitude (vector) and delay may be adjusted to compensate for downstream errors that are introduced and detected by a feedback circuit. Accordingly, the baseband processor, by monitoring an output of an analog hybrid matrix producing modulated and amplified radio frequency (RF) signals just prior to propagation from an antenna, can determine errors produced by the analog circuitry including the analog hybrid matrix and may compensate for the same by introducing an amplitude, phase and delay adjustment (in the digital domain) into output digital waveform signals to compensate for the error introduced downstream to the baseband processor.

Claims

1. A radio transmitter, comprising:

baseband processor means further including means for producing a plurality of transformed digital waveform signals wherein each of the plurality of transformed digital waveform signals include digital representations of portions of each of a plurality of analog signals;

a digital-to-analog conversion module for converting each of the plurality of transformed digital waveform signals from a digital domain to an analog domain;

an up-conversion module for converting a plurality of transformed analog signals produced by the digital-to-analog conversion module to a radio frequency (RF);

a power amplification module for amplifying a plurality of transformed RF analog signals produced by the up-conversion module; and

a hybrid matrix means for producing amplified RF analog signals wherein each of the plurality of amplified RF analog signals consists of approximately only one analog signal for transmission into a cell sector.

2. The radio transmitter of claim 1 further including feedback means coupled to receive and produce the plurality of amplified RF analog signals and to the baseband processor means by way of an analog-to-digital conversion module.

3. The radio transmitter of claim 2 wherein the feedback means comprises a plurality of directional couplers coupled to receive the plurality of amplified RF analog signals.

4. The radio transmitter of claim 1 wherein the hybrid matrix means comprises an N×

N hybrid matrix wherein “

N”

is greater than or equal to 3.

5. A method for generating forward link communication signals, comprising:

producing, in a baseband processor, a plurality of transformed digital waveform signals wherein each of the plurality of transformed digital waveform signals include digital representations of portions of each of a plurality of analog signals;

converting, in a digital-to-analog conversion module, each of the plurality of transformed digital waveform signals from a digital domain to an analog domain to create a plurality of transformed analog signals;

converting, in an up-conversion module, the plurality of transformed analog signals produced by the digital-to-analog conversion module from a baseband frequency to create a plurality of transformed radio frequency (RF) analog signals;

power amplifying the plurality of transformed RF analog signals produced by the up-conversion module; and

producing, in a hybrid matrix module, coupled to receive the plurality of transformed RF analog signals, a plurality of amplified RF analog signals wherein each of the plurality of amplified RF analog signals consists of approximately one analog signal for transmission into a cell sector.

6. The method of claim 5 further including receiving the plurality of amplified RF analog signals and converting the plurality of amplified RF analog signals to the digital domain after down-conversion to baseband.

7. The method of claim 6 further including producing the plurality of amplified RF analog signals converted to the digital domain to the baseband processor.

8. The method of claim 7 further including determining a vector and delay error of the plurality of amplified RF analog signals.

9. The method of claim 8 further including introducing a phase adjustment into the digital representations of each of the plurality of RF analog signals prior to producing a plurality of transformed and adjusted digital waveform signals to compensate for a determined phase error.

10. The method of claim 8 further including introducing an amplitude adjustment into the digital representations of each of the plurality of RF analog signals prior to producing the plurality of transformed digital waveform signals to compensate for the determined phase error.

11. The method of claim 8 further including introducing a delay adjustment into the digital representations of each of the plurality of RF analog signals prior to producing the plurality of transformed digital waveform signals to compensate for the determined phase error.