US 7,248,656 B2 · Digital convertible radio SNR optimization

Abstract

A digital convertible radio optimizes signal-to-noise ratios by substantially canceling undesired components of a plurality of input data streams present in sector signals in a cellular network. The sector output power is then scaled to optimize the total power at the sector output ports. The input data streams are cross-correlated with each other and with digital representations of the sector signals to produce a plurality of cross-correlated signals. The plurality of cross-correlated signals is combined to identify the undesired cross-correlated signals. The portion of the undesired signal measurement representing the correlation between the input signal streams are removed using the input signal cross correlation and system transfer function determination. A weighted vector adjustment module produces a plurality of complex weighted vector values that are mixed with the plurality of input data streams. Each weighted vector value is incrementally and sequentially adjusted based, in part, on measured undesired power levels. The real and imaginary components of the weighted vector value are updated with an incremented or decremented value that produces the lowest measured undesired power level.

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Drawings

Claims23

Dependent claims

A method in a digitally convertible radio (DCR) for optimizing a signal-to-noise ratio (SNR) in a multi-port system, the method comprising:

receiving a plurality of input digital data streams, the digital data of the input data streams further having magnitude and phase components wherein the plurality is equal to “N” input digital data streams;
creating a corresponding plurality of mixed input data streams from the plurality of input data streams and a plurality of weighted vector values, each of the plurality of mixed input data streams including magnitude and phase components of all the plurality of input data streams wherein the corresponding plurality is equal to “N”;
converting the plurality of mixed input data streams to a plurality of analog mixed signals;
amplifying the plurality of analog mixed signals;
producing, in an analog hybrid matrix, a plurality of sector signals from the plurality of amplified analog mixed signals, respectively, wherein:
the first sector signal comprising a maximum first sector signal, a minimal second sector signal component, and a minimal third sector signal component;
the second sector signal comprising a maximum second sector signal, a minimal first sector signal component, and a minimal third sector signal component;
and
the third sector signal comprising a maximum third sector signal, a minimal first sector signal component, a minimal second sector signal component;
transmitting the first, second, and third sector signals from antennas coupled to a first output port, a second output port, and a third output port, respectively;
correlating digital domain representations of the first, second, and third sector signals with the plurality of input data streams to produce a plurality of sector cross-correlated signals;
correlating the plurality of input data streams with each other to produce a plurality of input cross-correlated signals;
substantially canceling the cross-correlation between input data streams present in the plurality of sector cross-correlated signals to produce a plurality of corrected sector cross-correlated signals, wherein:
the step of substantially canceling the cross-correlation substantially removes, from a single sector cross-correlated signal, the correlated components of all other sector cross-correlated signals;
producing normalized power feedback signals from the plurality of corrected sector cross-correlated signals;
and
determining, from the normalized power feedback signals, a plurality of weighted vector values.

14 more elements

A digital convertible radio comprising:

a digital hybrid matrix (DHM) for producing a plurality of mixed input data streams from a plurality of input digital data streams and a plurality of weighted vector values, wherein each of the plurality of mixed input data streams includes magnitude and phase components from each of the plurality of input data streams;
an up-conversion module operably coupled to receive the plurality of mixed input data streams from the DHM, the up-conversion module for converting the plurality of mixed input data streams from a digital domain to an analog domain and for up-converting the analog domain signals to a radio frequency (RF) to produce a plurality of analog RF mixed signals;
an amplifier module further including a plurality of amplifiers for receiving and amplifying the plurality of analog RF mixed signals;
an N×N analog hybrid matrix (AHM) coupled to receive the N amplified analog RF mixed signals, the AHM for producing M sector signals, wherein M is equal to or less than N, and wherein each sector signal, of the M sector signals, comprises a maximum component of that sector signal and minimal components of all other sector signals;
a plurality of transmitting antennas for transmitting the M sector signals received from the N×N analog hybrid matrix;
a down-conversion module operably coupled to receive the M sector signals from the ARM, the down-conversion module for:
converting the M sector signals from the analog domain to the digital domain to produce M converted sector signals, wherein the M converted sector signals are digital domain representations of the M sector signals;
and
down-converting the digital domain signals to a baseband frequency;
a correlation module for producing a N2 sector cross-correlated signals and 2*N input cross-correlated signals from the received M converted sector signals, and from the N received input data streams;
a cancellation module operably coupled to receive M2 sector cross-correlated signals and 2*N input cross-correlated signals and to produce M2 corrected sector cross-correlated signals;
a power determination module operably coupled to receive the M2 corrected sector cross-correlated signals, the power determination module for producing a plurality of normalized power feedback signals from the received M2 corrected sector cross-correlated signals;
and
a weighted vector adjustment module operably coupled to receive the plurality of normalized power feedback signals, the weighted vector adjustment module further producing a plurality of weighted vector values, wherein the plurality of weighted vector values function to minimize undesired signal components in the plurality of sector signals.

11 more elements

A weighted vector adjustment module of a digital convertible radio, comprising:

a digital processor for storing and executing computer instructions that define operational logic for processing a plurality of normalized power feedback signals, the digital processor further including computer instructions that define logic for generating a plurality of weighted vector values;
a bus coupled to the digital processor for transmitting signals to and from the digital processor within the weighted vector adjustment module;
an input/output module coupled to the bus, the input/output module for receiving the plurality of normalized power feedback signals from a power determination module and for coupling the plurality of weighted vector values to a digital hybrid matrix (DHM);
and
memory coupled to the bus, the memory for storing data.

2 more elements

Dependencies are inferred from the claim text.

Description9,126 words

Summary1,828 words

#1. Technical Field of the Invention

#This invention relates generally to wireless communication systems and, more particularly, to radio frequency (RF) transmitters used within radio transceivers of such wireless communication systems.

#2. Description of Related Art

Brief description of the drawings11 figures

#FIG. 1 is a functional block diagram of a prior art cellular network cell having three cell sectors;

#FIG. 2 is a prior art transmitter that includes a pair of analog hybrid matrices;

#FIG. 3 is a functional block diagram of a radio transmitter formed according to one embodiment of the present invention;

Detailed description7,092 words

#These and other features, aspects and advantages of the present invention will be more fully understood when considered with respect to the following detailed description, appended claims and accompanying drawings.

#FIG. 3 is a functional block diagram of a radio transmitter formed according to one embodiment of the present invention. A baseband processor 30 includes a plurality of modules that produce a plurality of transformed and adjusted digital waveform signals having compensation components that compensate for errors that are introduced downstream. More specifically, a first processing module 32 generates a plurality of digital waveform signals, each of which is a digital bit stream that represents an analog radio frequency (RF) signal (i.e., a digital representation of an “analog” RF signal) that is to be transmitted to a cell sector. A second processing module 34 receives the plurality of digital waveform signals and produces 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 RF analog signals represented by the plurality of digital waveform signals produced by the first processing module 32.

#The second processing module 34 includes an indirect vector and delay detection module 36 and a vector and delay compensated transformation module 38. The indirect vector and delay detection module 36 uses the amplitude of the signals at the output ports to determine the degree of summation and cancellation. Based on the degree of summation and cancellation, the vector and delay compensated transformation module 38 is formed to introduce either one or both of a vector and delay component to the plurality of digital waveform signals by adjusting the vector and delay compensated transformation module 38. A plurality of transformed digital waveform signals produced by the second processing module 34 of the baseband processor 30 is thus modified in amplitude, phase and delay according to detected vector and delay errors introduced downstream. A third baseband processor 40 then applies a number of further processing functions to each of the plurality of transformed digital waveform signals at the output of the second processing module 34. The functions include baseband pre-distortion, peak power reduction and a number of filter functions. The baseband processor 30 and, more specifically, the third processing module 40, then produces the plurality of transformed and adjusted digital. waveform signals to a digital-to-analog conversion module 46 wherein the plurality of transformed and adjusted digital waveform signals are converted from a digital domain to an analog domain to create a plurality of transformed analog signals. The converted plurality of transformed analog signals are then produced by the digital-to-analog conversion module 46 to an up-conversion module 48 where they are up-converted from a baseband frequency to a radio frequency (RF) to create a plurality of transformed RF analog signals.

Facts

Application

10/670,426Filed 24 Sep 2003 · continuation in part

Priority

2 Dec 2002

Published

US 2004/0105509 A118 Nov 2004

Granted

24 Jul 2007

Term ended

7 Nov 2024

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 706 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification13 codes

H04B 1/0483
Circuits: transmitters with multiple parallel paths
H03F 1/3241
Modifications of amplifiers to reduce non-linear distortion: using predistortion circuits
H03F 1/3247
Using predistortion circuits: using feedback acting on predistortion circuits
H03F 1/3282
Using predistortion circuits: acting on the phase and the amplitude of the input signal

Family

Application10/307,624Parent of this continuation-in-part · filed 2 Dec 2002

US 2004/0228422 A1Pre-grant publication · published 18 Nov 2004

US 2004/0105509 A1Published application

US 7,206,355 B2Related patent

US 7,248,656 B2This patent

From the US filing history. Foreign family members aren’t listed.

Timeline

2 Dec 2002Priority claimedParent application 10/307,624
24 Sep 2003Application filedUS 10/670,426
24 Sep 2003Assigned to Nortel Networks Limitedassignment of assignor's interest
18 Nov 2004PublishedUS 2004/0105509 A1
24 Jul 2007GrantedUS 7,248,656 B2
28 Oct 2011Assigned to Rockstar Bidco, LPassignment of assignor's interest
30 Jul 2012Assigned to Apple Inc.assignment of assignor's interest
7 Nov 2024Term endedEstimated, includes 706 days of adjustment

Digital convertible radio SNR optimization

Life of this patent

Digital convertible radio SNR optimization

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims23

Description9,126 words

Drawings

Classification13 codes

Life of this patent

Description9,126 words