U.S. patent application number 13/692854 was filed with the patent office on 2013-10-03 for tunable notch filter using feedback through an existing feedback receiver.
This patent application is currently assigned to QUALCOMM INCORPORATED. The applicant listed for this patent is QUALCOMM INCORPORATED. Invention is credited to Ojas M Choksi, Prasad Srinivasa Siva Gudem, Wei Zhuo.
Application Number | 20130259099 13/692854 |
Document ID | / |
Family ID | 49234990 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130259099 |
Kind Code |
A1 |
Gudem; Prasad Srinivasa Siva ;
et al. |
October 3, 2013 |
TUNABLE NOTCH FILTER USING FEEDBACK THROUGH AN EXISTING FEEDBACK
RECEIVER
Abstract
A wireless communication device configured for reducing Tx
leakage in a receive signal is described. The wireless
communication device includes a transceiver chip. The transceiver
chip includes a receiver, a feedback receiver and a transmitter.
The wireless communication device also includes a Tx leakage signal
reduction module. The Tx leakage signal reduction module reuses the
feedback receiver.
Inventors: |
Gudem; Prasad Srinivasa Siva;
(San Diego, CA) ; Choksi; Ojas M; (San Diego,
CA) ; Zhuo; Wei; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM INCORPORATED |
San Diego |
CA |
US |
|
|
Assignee: |
QUALCOMM INCORPORATED
San Diego
CA
|
Family ID: |
49234990 |
Appl. No.: |
13/692854 |
Filed: |
December 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61618483 |
Mar 30, 2012 |
|
|
|
Current U.S.
Class: |
375/219 ;
455/79 |
Current CPC
Class: |
H04B 1/525 20130101;
H04B 17/354 20150115; H04B 1/44 20130101; H04B 1/1036 20130101;
H04B 1/3805 20130101; H04B 17/24 20150115 |
Class at
Publication: |
375/219 ;
455/79 |
International
Class: |
H04B 1/44 20060101
H04B001/44 |
Claims
1. A wireless communication device configured for reducing Tx
leakage in a receive signal, comprising: a transceiver chip,
comprising: a receiver; a feedback receiver; and a transmitter; and
a Tx leakage signal reduction module, wherein the Tx leakage signal
reduction module reuses the feedback receiver.
2. The wireless communication device of claim 1, wherein the Tx
leakage signal reduction module comprises a notch filter that
reduces Tx leakage in the receive signal.
3. The wireless communication device of claim 2, wherein the notch
filter is located on the transceiver chip, and wherein the notch
filter is coupled to an output of a low noise amplifier that
receives the receive signal.
4. The wireless communication device of claim 2, wherein the notch
filter is located off the transceiver chip, wherein the notch
filter receives the receive signal, and wherein an output of the
notch filter is coupled to an input of a low noise amplifier on the
transceiver chip.
5. The wireless communication device of claim 1, wherein the
receiver provides a feedback signal to the feedback receiver, and
wherein the feedback receiver provides a digital leakage reduction
signal to the Tx leakage signal reduction module.
6. The wireless communication device of claim 5, wherein the
digital leakage reduction signal tunes a notch filter in the Tx
leakage signal reduction module to minimize Tx leakage in the
receive signal.
7. The wireless communication device of claim 6, wherein the notch
filter comprises a first variable capacitor, a second variable
capacitor, a first resistor, a second resistor and an inductor.
8. The wireless communication device of claim 6, wherein the notch
filter is tuned to provide reliable rejection of Tx leakage across
process, voltage and temperature.
9. The wireless communication device of claim 5, wherein the
digital leakage reduction signal tunes a balancing impedance in a
hybrid transformer on the wireless communication device.
10. The wireless communication device of claim 9, wherein the
hybrid transformer comprises a first inductor, a second inductor
and a third inductor, and wherein the balancing impedance is
coupled between the second inductor and ground.
11. The wireless communication device of claim 5, wherein the
feedback signal is provided to a feedback downconverter in the
feedback receiver by a first amplifier in a cascode stage in the
receiver.
12. The wireless communication device of claim 11, wherein an
output of the feedback downconverter is coupled to an
analog-to-digital converter via a feedback baseband filter, and
wherein an output of the analog-to-digital converter is converted
to the digital leakage reduction signal by a digital signal
processor.
13. A method for reducing Tx leakage in a receive signal,
comprising: receiving the receive signal; processing the receive
signal in a receiver; providing a feedback signal from the receiver
to a feedback downconverter; converting the feedback signal to a
digital leakage reduction signal using an analog-to-digital
converter and a digital signal processor; and using the digital
leakage reduction signal to reduce Tx leakage in the receive
signal.
14. The method of claim 13, further comprising: downconverting the
feedback signal using the feedback downconverter; and filtering the
downconverted feedback signal using a feedback baseband filter.
15. The method of claim 13, wherein processing the receive signal
in the receiver comprises passing the receive signal through a
notch filter.
16. The method of claim 13, wherein the method is performed by a
wireless communication device comprising: a transceiver chip,
comprising: the receiver; a feedback receiver; and a transmitter;
and a Tx leakage signal reduction module, wherein the Tx leakage
signal reduction module reuses the feedback receiver.
17. The method of claim 16, wherein the Tx leakage signal reduction
module comprises a notch filter, and further comprising performing
process tuning on the notch filter using the digital leakage
reduction signal.
18. The method of claim 17, wherein the notch filter is located on
the transceiver chip, and wherein the notch filter is coupled to an
output of a low noise amplifier that receives the receive
signal.
19. The method of claim 17, wherein the notch filter is located off
the transceiver chip, wherein the notch filter receives the receive
signal, and wherein an output of the notch filter is coupled to an
input of a low noise amplifier on the transceiver chip.
20. The method of claim 16, wherein the receiver provides the
feedback signal to the feedback receiver, and wherein the feedback
receiver provides the digital leakage reduction signal to the Tx
leakage signal reduction module.
21. The method of claim 20, wherein the digital leakage reduction
signal tunes a notch filter in the Tx leakage signal reduction
module to minimize Tx leakage in the receive signal.
22. The method of claim 21, wherein the notch filter comprises a
first variable capacitor, a second variable capacitor, a first
resistor, a second resistor and an inductor.
23. The method of claim 22, further comprising: determining a
measured notch frequency of the notch filter; determining a process
error; calculating a first capacitor code and a second capacitor
code that meet requirements for a channel; and applying the first
capacitor code to the first variable capacitor and the second
capacitor code to the second variable capacitor.
24. The method of claim 23, wherein determining a measured notch
frequency of the notch filter comprises: applying a transmit tone
on three different frequencies to the notch filter; measuring a DC
gain through the feedback receiver; calculating a gradient; and
determining the measured notch frequency using a gradient search
algorithm.
25. The method of claim 21, wherein the notch filter is tuned to
provide reliable rejection of Tx leakage across process, voltage
and temperature.
26. The method of claim 20, wherein the digital leakage reduction
signal tunes a balancing impedance in a hybrid transformer on the
wireless communication device.
27. The method of claim 26, wherein the hybrid transformer
comprises a first inductor, a second inductor and a third inductor,
and wherein the balancing impedance is coupled between the second
inductor and ground.
28. The method of claim 20, wherein the feedback signal is provided
to a feedback downconverter in the feedback receiver by a first
amplifier in a cascode stage in the receiver.
29. The method of claim 28, wherein an output of the feedback
downconverter is coupled to an analog-to-digital converter via a
feedback baseband filter, and wherein an output of the
analog-to-digital converter is provided to a digital signal
processor that outputs the digital leakage reduction signal.
30. An apparatus for reducing Tx leakage in a receive signal,
comprising: means for receiving the receive signal; means for
processing the receive signal in a receiver; means for providing a
feedback signal from the receiver to a feedback downconverter;
means for converting the feedback signal to a digital leakage
reduction signal; and means for using the digital leakage reduction
signal to reduce Tx leakage in the receive signal.
31. The apparatus of claim 30, further comprising: means for
downconverting the feedback signal; and means for filtering the
downconverted feedback signal.
32. The apparatus of claim 30, wherein the means for processing the
receive signal in the receiver comprise means for passing the
receive signal through a notch filter.
33. The apparatus of claim 30, wherein the apparatus is a wireless
communication device comprising: a transceiver chip, comprising:
the receiver; a feedback receiver; and a transmitter; and a Tx
leakage signal reduction module, wherein the Tx leakage signal
reduction module reuses the feedback receiver.
34. A computer-program product for reducing Tx leakage in a receive
signal, the computer-program product comprising a non-transitory
computer-readable medium having instructions thereon, the
instructions comprising: code for causing a wireless communication
device to receive the receive signal; code for causing the wireless
communication device to process the receive signal in a receiver;
code for causing the wireless communication device to provide a
feedback signal from the receiver to a feedback downconverter; code
for causing the wireless communication device to convert the
feedback signal to a digital leakage reduction signal using an
analog-to-digital converter and a digital signal processor; and
code for causing the wireless communication device to use the
digital leakage reduction signal to reduce Tx leakage in the
receive signal.
35. The computer-program product of claim 34, wherein the
instructions further comprise: code for causing the wireless
communication device to downconvert the feedback signal; and code
for causing the wireless communication device to filter the
downconverted feedback signal.
36. The computer-program product of claim 34, wherein the code for
causing the wireless communication device to process the receive
signal in the receiver comprise code for causing the wireless
communication device to pass the receive signal through a notch
filter.
37. The computer-program product of claim 34, wherein the wireless
communication device comprises: a transceiver chip, comprising: the
receiver; a feedback receiver; and a transmitter; and a Tx leakage
signal reduction module, wherein the Tx leakage signal reduction
module reuses the feedback receiver.
Description
CLAIM OF PRIORITY UNDER 35 U.S.C. X119
[0001] The present Application for Patent claims priority to
Provisional Application No. 61/618,483, entitled "Tunable notch
filter using feedback through an existing envelope tracking (ET)
receiver" filed Mar. 30, 2012, and assigned to the assignee hereof
and hereby expressly incorporated by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates generally to wireless devices
for communication systems. More specifically, the present
disclosure relates to systems and methods for a tunable notch
filter using feedback through an existing feedback receiver.
BACKGROUND
[0003] Electronic devices (cellular telephones, wireless modems,
computers, digital music players, Global Positioning System units,
Personal Digital Assistants, gaming devices, etc.) have become a
part of everyday life. Small computing devices are now placed in
everything from automobiles to housing locks. The complexity of
electronic devices has increased dramatically in the last few
years. For example, many electronic devices have one or more
processors that help control the device, as well as a number of
digital circuits to support the processor and other parts of the
device.
[0004] Electronic devices may transmit and receive wireless signals
simultaneously. Because of the distance between an electronic
device and a base station, wireless signals received by the
electronic device may have considerably less amplitude than
wireless signals transmitted by the electronic device. As such,
portions of the transmit signal may leak onto the received signals,
reducing the signal quality of the received signals. These leaked
transmit signals may be filtered out. However, non-adaptive filters
are limited in both the amount of signal removed and the frequency
band of the signal removed. Benefits may be realized by using
adaptive filters that adapt to the leakage signal that appears on
the received signal.
SUMMARY
[0005] A wireless communication device configured for reducing Tx
leakage in a receive signal is described. The wireless device
includes a transceiver chip. The transceiver chip includes a
receiver, a feedback receiver and a transmitter. The transceiver
chip also includes a Tx leakage signal reduction module. The Tx
leakage signal reduction module reuses the feedback receiver.
[0006] The Tx leakage signal reduction module may include a notch
filter that reduces Tx leakage in the receive signal. The notch
filter may be located on the transceiver chip. The notch filter may
be coupled to an output of a low noise amplifier that receives the
receive signal. The notch filter may instead be located off the
transceiver chip. The notch filter may receive the receive signal.
An output of the notch filter may be coupled to an input of a low
noise amplifier on the transceiver chip.
[0007] The receiver may provide a feedback signal to the feedback
receiver. The feedback receiver may provide a digital leakage
reduction signal to the Tx leakage signal reduction module. The
digital leakage reduction signal may tune a notch filter in the Tx
leakage signal reduction module to minimize Tx leakage in the
receive signal. The notch filter may include a first variable
capacitor, a second variable capacitor, a first resistor, a second
resistor and an inductor. The notch filter may be tuned to provide
reliable rejection of Tx leakage across process, voltage and
temperature. The digital leakage reduction signal may tune a
balancing impedance in a hybrid transformer on the wireless
communication device.
[0008] The hybrid transformer may include a first inductor, a
second inductor and a third inductor. The balancing impedance may
be coupled between the second inductor and ground. The feedback
signal may be provided to a feedback downconverter in the feedback
receiver by a first amplifier in a cascode stage in the receiver.
An output of the feedback downconverter may be coupled to an
analog-to-digital converter via a feedback baseband filter. An
output of the analog-to-digital converter may be converted to the
digital leakage reduction signal by a digital signal processor.
[0009] A method for reducing Tx leakage in a receive signal is also
described. The receive signal is received. The receive signal is
processed in a receiver. A feedback signal is provided from the
receiver to a feedback downconverter. The feedback signal is
converted to a digital leakage reduction signal using an
analog-to-digital converter and a digital signal processor. The
digital leakage reduction signal is used to reduce Tx leakage in
the receive signal.
[0010] The feedback signal may be downconverted using the feedback
downconverter. The downconverted feedback signal may be filtered
using a feedback baseband filter. Processing the receive signal in
the receiver may include passing the receive signal through a notch
filter.
[0011] A measured notch frequency of the notch filter may be
determined A process error may also be determined A first capacitor
code and a second capacitor code may be calculated that meet
requirements for a channel. The first capacitor code may be applied
to the first variable capacitor and the second capacitor code may
be applied to the second variable capacitor.
[0012] Determining a measured notch frequency of the notch filter
may include applying a transmit tone on three different frequencies
to the notch filter, measuring a DC gain through the feedback
receiver, calculating a gradient and determining the measured notch
frequency using a gradient search algorithm.
[0013] An apparatus for reducing Tx leakage in a receive signal is
described. The apparatus includes means for receiving the receive
signal. The apparatus also includes means for processing the
receive signal in a receiver. The apparatus further includes means
for providing a feedback signal from the receiver to a feedback
downconverter. The apparatus also includes means for converting the
feedback signal to a digital leakage reduction signal. The
apparatus further includes means for using the digital leakage
reduction signal to reduce Tx leakage in the receive signal.
[0014] A computer-program product for reducing Tx leakage in a
receive signal is also described. The computer-program product
includes a non-transitory computer-readable medium having
instructions thereon. The instructions include code for causing a
wireless communication device to receive the receive signal. The
instructions also include code for causing the wireless
communication device to process the receive signal in a receiver.
The instructions further include code for causing the wireless
communication device to provide a feedback signal from the receiver
to a feedback downconverter. The instructions also include code for
causing the wireless communication device to convert the feedback
signal to a digital leakage reduction signal using an
analog-to-digital converter and a digital signal processor. The
instructions further include code for causing the wireless
communication device to use the digital leakage reduction signal to
reduce Tx leakage in the receive signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a wireless communication device for use in the
present systems and methods;
[0016] FIG. 2 is a flow diagram of a method for minimizing a Tx
leakage signal in a primary receive signal;
[0017] FIG. 3 is a block diagram illustrating a transceiver chip
that includes a Tx leakage signal reduction module;
[0018] FIG. 4 is a block diagram illustrating another transceiver
chip that includes a Tx leakage signal reduction module;
[0019] FIG. 5 is a flow diagram of another method for minimizing a
Tx leakage signal in a primary receive signal;
[0020] FIG. 6 is a block diagram illustrating Tx leakage signal
reduction using an integrated duplexer;
[0021] FIG. 7 is a circuit diagram illustrating a notch filter;
[0022] FIG. 8 is a flow diagram of a method for process tuning a
notch filter;
[0023] FIG. 9 is a flow diagram of a method for finding the
measured notch frequency of a notch filter; and
[0024] FIG. 10 illustrates certain components that may be included
within a wireless communication device.
DETAILED DESCRIPTION
[0025] The 3.sup.rd Generation Partnership Project (3GPP) is a
collaboration between groups of telecommunications associations
that aims to define a globally applicable 3.sup.rd generation (3G)
mobile phone specification. 3GPP Long Term Evolution (LTE) is a
3GPP project aimed at improving the Universal Mobile
Telecommunications System (UMTS) mobile phone standard. The 3GPP
may define specifications for the next generation of mobile
networks, mobile systems and mobile devices. In 3GPP LTE, a mobile
station or device may be referred to as a "user equipment"
(UE).
[0026] 3GPP specifications are based on evolved Global System for
Mobile Communications (GSM) specifications, which are generally
known as the Universal Mobile Telecommunications System (UMTS).
3GPP standards are structured as releases. Discussion of 3GPP thus
frequently refers to the functionality in one release or another.
For example, Release 99 specifies the first UMTS third generation
(3G) networks, incorporating a CDMA air interface. Release 6
integrates operation with wireless local area networks (LAN)
networks and adds High Speed Uplink Packet Access (HSUPA). Release
8 introduces dual downlink carriers and Release 9 extends dual
carrier operation to uplink for UMTS.
[0027] CDMA2000 is a family of 3.sup.rd generation (3G) technology
standards that use code division multiple access (CDMA) to send
voice, data and signaling between wireless devices. CDMA2000 may
include CDMA2000 1.times., CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO
Rev. A and CDMA2000 EV-DO Rev. B. 1.times. or 1.times.RTT refers to
the core CDMA2000 wireless air interface standard. 1.times. more
specifically refers to 1 times Radio Transmission Technology and
indicates the same radio frequency (RF) bandwidth as used in IS-95.
1.times.RTT adds 64 additional traffic channels to the forward
link. EV-DO refers to Evolution-Data Optimized. EV-DO is a
telecommunications standard for the wireless transmission of data
through radio signals.
[0028] FIG. 1 shows a wireless communication device 104 for use in
the present systems and methods. A wireless communication device
104 may also be referred to as, and may include some or all of the
functionality of, a terminal, an access terminal, a user equipment
(UE), a subscriber unit, a station, etc. A wireless communication
device 104 may be a cellular phone, a personal digital assistant
(PDA), a wireless device, a wireless modem, a handheld device, a
laptop computer, a PC card, compact flash, an external or internal
modem, a wireline phone, etc. A wireless communication device 104
may be mobile or stationary. A wireless communication device 104
may communicate with zero, one or multiple base stations on a
downlink and/or an uplink at any given moment. The downlink (or
forward link) refers to the communication link from a base station
to a wireless communication device 104, and the uplink (or reverse
link) refers to the communication link from a wireless
communication device 104 to a base station. Uplink and downlink may
refer to the communication link or to the carriers used for the
communication link.
[0029] A wireless communication device 104 may operate in a
wireless communication system that includes other wireless devices,
such as base stations. A base station is a station that
communicates with one or more wireless communication devices 104. A
base station may also be referred to as, and may include some or
all of the functionality of, an access point, a broadcast
transmitter, a Node B, an evolved Node B, etc. Each base station
provides communication coverage for a particular geographic area. A
base station may provide communication coverage for one or more
wireless communication devices 104. The term "cell" can refer to a
base station and/or its coverage area, depending on the context in
which the term is used.
[0030] Communications in a wireless communication system (e.g., a
multiple-access system) may be achieved through transmissions over
a wireless link. Such a communication link may be established via a
single-input and single-output (SISO) or a multiple-input and
multiple-output (MIMO) system. A multiple-input and multiple-output
(MIMO) system includes transmitter(s) and receiver(s) equipped,
respectively, with multiple (NT) transmit antennas and multiple
(NR) receive antennas for data transmission. SISO systems are
particular instances of a multiple-input and multiple-output (MIMO)
system. The multiple-input and multiple-output (MIMO) system can
provide improved performance (e.g., higher throughput, greater
capacity or improved reliability) if the additional
dimensionalities created by the multiple transmit and receive
antennas are utilized.
[0031] The wireless communication system may utilize both
single-input and multiple-output (SIMO) and multiple-input and
multiple-output (MIMO). The wireless communication system may be a
multiple-access system capable of supporting communication with
multiple wireless communication devices 104 by sharing the
available system resources (e.g., bandwidth and transmit power).
Examples of such multiple-access systems include code division
multiple access (CDMA) systems, wideband code division multiple
access (W-CDMA) systems, time division multiple access (TDMA)
systems, frequency division multiple access (FDMA) systems,
orthogonal frequency division multiple access (OFDMA) systems,
single-carrier frequency division multiple access (SC-FDMA)
systems, 3.sup.rd Generation Partnership Project (3GPP) Long Term
Evolution (LTE) systems and spatial division multiple access (SDMA)
systems.
[0032] The wireless communication device 104 may include a primary
antenna 106 and a secondary antenna 108. In one configuration, the
primary antenna 106 may be used for transmitting wireless signals
and receiving a primary signal while the secondary antenna 108 may
be used for receiving a secondary signal. Both the primary antenna
106 and the secondary antenna 108 may be coupled to a transceiver
chip 110 on the wireless communication device 104.
[0033] The transceiver chip 110 may include a transmitter 112, a
primary receiver (PRx) 114, a diversity receiver (DRx) 116, a
feedback receiver 147 and a Tx leakage signal reduction module 118.
The Tx leakage signal reduction module include a notch filter or an
adjustable impedance. In one configuration, portions of the Tx
leakage signal reduction module 118 may be located on the
transceiver chip 110 while other portions of the Tx leakage signal
reduction module 118 may be located off the transceiver chip
110.
[0034] In full duplex systems, wireless devices may transmit and
receive simultaneously. The transmit frequency and the receive
frequency may be separated to prevent interference. Typically, the
transmit signal broadcast by a wireless device has a significantly
larger amplitude than the signals received by the wireless device.
This is due to the attenuation of wireless signals (i.e., received
signals have attenuated during wireless travel while transmit
signals need higher amplitude to ensure proper reception). For this
reason, transmit signals often interfere with receive signals. The
noise from the transmit signal that interferes with the receive
signal may be referred to as the Tx leakage signal. It is desirable
to reduce or eliminate the Tx leakage signal in the receive signal.
The Tx leakage signal may be removed using filters. The Tx leakage
signal reduction module 118 may reduce the amplitude of the Tx
leakage signal using feedback while simultaneously improving the
second order intercept point (IIP2) and Rx local oscillator (LO)
phase noise requirements. It is desirable for the Tx leakage signal
reduction module 118 to reuse an existing feedback receiver. In one
configuration, the Tx leakage signal reduction module 118 may
improve the second order intercept point (IIP2) without burning a
significant amount of current.
[0035] In one configuration, the use of the Tx leakage signal
reduction module may allow for the elimination of an external
diversity surface acoustic wave (SAW) filter on the wireless
communication device 104. Removing an external diversity surface
acoustic wave (SAW) filter on the wireless communication device 104
may reduce the cost, size and power consumption of the wireless
communication device 104.
[0036] FIG. 2 is a flow diagram of a method 200 for minimizing a Tx
leakage signal in a primary receive signal. The method 200 may be
performed by a wireless communication device 104. In one
configuration, the method 200 may be performed by a Tx leakage
signal reduction module 118 on a transceiver chip 110 in the
wireless communication device 104. The wireless communication
device 104 may receive 202 a receive signal. The receive signal may
be received by the primary antenna 106. The receive signal may
include the desired receive signal and a Tx leakage signal.
[0037] The wireless communication device 104 may process 204 the
receive signal in a receiver. In one configuration, the wireless
communication device 104 may process 204 the receive signal in a
primary receiver (PRx) 114 or a diversity receiver (DRx) 116. The
wireless communication device 104 may provide 206 a feedback signal
from the receiver to a feedback downconverter in a feedback
receiver. In one configuration, the feedback signal may be output
from a cascode stage in the receiver. The wireless communication
device 104 may then downconvert 208 the frequency of the feedback
signal using the feedback downconverter in the feedback receiver.
The wireless communication device 104 may filter 210 the feedback
signal in the feedback receiver. The wireless communication device
104 may then convert 212 the feedback signal to a digital leakage
reduction signal using an analog-to-digital converter (ADC) and a
digital signal processor (DSP). In one configuration, the digital
signal processor (DSP) may be located on a modem.
[0038] The wireless communication device 104 may apply 214 the
digital leakage reduction signal to a Tx leakage signal reduction
module 118 to minimize the Tx leakage signal in the receive signal.
For example, the digital leakage reduction signal may be used to
adjust the values of a notch filter. The notch filter may be part
of the receiver. Alternatively, the notch filter may be located off
the transceiver chip 110 on the wireless communication device 104.
The notch filter may filter out the Tx leakage signal prior to the
cascode stage. Thus, the configuration of the notch filter may be
adjusted using feedback to minimize the Tx leakage signal in the
receive signal. As another example, the digital leakage reduction
signal may be used to adjust a tunable impedance in a hybrid
transformer on the wireless communication device 104. Adjusting a
tunable impedance in a hybrid transformer is discussed in
additional detail below in relation to FIG. 6. Adjusting the
tunable impedance may reduce the Tx leakage signal in the wireless
signal.
[0039] FIG. 3 is a block diagram illustrating a transceiver chip
310 that includes a Tx leakage signal reduction module 318. The
transceiver chip 310 of FIG. 3 may be one configuration of the
transceiver chip 110 of FIG. 1. The transceiver chip 310 may
include a transmitter 312, a feedback receiver 347 and a receiver
314. The receiver 314 may be a primary receiver (PRx) or a
diversity receiver (DRx). In one configuration, the feedback
receiver 347 may be part of the transmitter 312.
[0040] The transmitter 312 may receive a Tx inphase/quadrature
(I/Q) signal 326. The Tx inphase/quadrature (I/Q) signal 326 may be
passed through a Tx baseband filter (BBF) 324 before being
upconverted to a transmit frequency by an upconverter 322. The
upconverted transmit signal may then be amplified by a drive
amplifier (DA) 320 before being transmitted. The transmitter 312
may include a phase lock loop (PLL) 334, a Tx voltage controlled
oscillator (VCO) 332 and a Div stage 330 that are used to generate
a Tx local oscillator (LO) signal 337. The Tx local oscillator (LO)
signal 337 may be provided to the upconverter 322.
[0041] The feedback receiver 347 may be used to regulate the
transmitter 312 (e.g., to provide periodic feedback about the power
levels of the transmitter 312 to ensure that the transmitter 312 is
transmitting with the proper amount of power). During regular
operation, the feedback receiver 347 may be off for considerable
amounts of time (to save power). In other words, the feedback
receiver 347 may normally be turned on for short amounts of time to
track the power of the transmitter 312 and then turned off. Thus,
the circuitry in the feedback receiver 347 may be reused to tune a
notch filter 350. For example, the feedback baseband filter (BBF)
342 and the Rx analog-to-digital converter (ADC) 344 may be reused
to tune the notch filter 350.
[0042] The circuitry in the feedback receiver 347 may include a
feedback low noise amplifier (LNA) 336 that receives transmit
signals. The output of the feedback low noise amplifier (LNA) 336
may be coupled to a feedback downconverter 338 that reuses the
synthesizer of the transmitter 312. Thus, the feedback
downconverter 338 may receive the Tx local oscillator (LO) signal
337. The output of the feedback downconverter 338 may be coupled to
a feedback baseband filter (BBF) 342. The feedback baseband filter
(BBF) 342 may output the feedback inphase/quadrature (I/Q) signal
354 to the modem. The output of the feedback baseband filter (BBF)
342 may also be passed through an analog-to-digital converter (ADC)
344 before being provided to the modem (although only one
analog-to-digital converter (ADC) 344 is shown, two
analog-to-digital converters (ADCs) 344 may be used, one for the
inphase signal and one for the quadrature signal).
[0043] To reuse the feedback receiver 347, the receiver 314 may
provide a feedback signal 343 to the feedback downconverter 338.
The feedback signal 343 may be current that is bled from a cascode
stage 348 in a Tx leakage signal reduction module 318. For example,
the cascode stage 348 may include a first amplifier 331a and a
second amplifier 331b. The output of the first amplifier 331a may
be provided to the feedback downconverter 338 as the feedback
signal 343. The feedback signal 343 may be either a voltage signal
or a current signal. In one configuration, the feedback signal 343
may be current bled from a cascode stage 348. The output of the
second amplifier 331b may be provided to a downconverter 351 on the
receiver 314 as the amplified receive signal 349. The feedback
signal 343 may provide feedback about a notch filter 350 in the Tx
leakage signal reduction module 318, allowing the notch filter 350
to be tuned. The feedback signal 343 may be processed by the
feedback receiver 347 (via the Rx analog-to-digital converter (ADC)
344) to obtain a digital leakage reduction signal 364. Additional
digital signal processing (e.g., by the modem) may be performed on
the output of the Rx analog-to-digital converter (ADC) 344 (such as
by a digital signal processor (DSP)) to obtain the digital leakage
reduction signal 364. The digital leakage reduction signal 364 may
be used to tune the Tx leakage signal reduction module 318 in the
receiver 314.
[0044] The receiver 314 may include a low noise amplifier (LNA)
346. The low noise amplifier (LNA) 346 may receive a receive signal
345. The receive signal 345 may include undesirable Tx leakage. To
reduce the Tx leakage in the receive signal 345, the primary 314
may include a Tx leakage reduction module 318. The Tx leakage
signal reduction module 318 may include the cascode stage 348 and
the notch filter 350. The notch filter 350 may be coupled to the
output of the low noise amplifier (LNA) 346. The notch filter 350
may also receive the digital leakage reduction signal 364. The
digital leakage reduction signal 364 may provide accurate notch
filter 350 tuning across process, voltage and temperature (PVT) to
minimize the Tx leakage in the receive signal 345. The Tx leakage
signal reduction module 318 may use existing hardware (such as the
feedback receiver 347) to reduce the Tx leakage signal (by tuning
the notch filter 350 to remove the Tx leakage signal).
[0045] The output of the low noise amplifier (LNA) 346 may be
coupled to the notch filter 350. The output of the notch filter 350
may be coupled to the cascode stage 348. As discussed above, the
cascode stage 348 may include a first amplifier 331a and a second
amplifier 331b. The output of the second amplifier may be provided
to a downconverter 351 on the receiver 314. In one configuration,
10% of the current is bled as the feedback signal 343.
[0046] The receiver 314 may include a phase lock loop (PLL) 362, an
Rx voltage controlled oscillator (VCO) 360 and a Div stage 358 that
provide an Rx local oscillator (LO) signal 339 to the downconverter
351. The downconverter 351 may convert signals to baseband
frequency. The output of the downconverter 351 may be coupled to an
Rx baseband filter (BBF) 352. The Rx baseband filter (BBF) 352 may
then output the inphase/quadrature (I/Q) signal 356. Using the
feedback receiver 347 to tune the notch filter 350 may provide
reliable rejection of the Tx leakage signal across process, voltage
and temperature (PVT).
[0047] FIG. 4 is a block diagram illustrating another transceiver
chip 410 that includes a Tx leakage signal reduction module 418.
The Tx leakage signal reduction module 418 may include a notch
filter 450 that is located off the transceiver chip 410. The
transceiver chip 410 of FIG. 4 may be one configuration of the
transceiver chip 110 of FIG. 1. The transceiver chip 410 may
include a transmitter 412, a feedback receiver 447 and a receiver
414. In one configuration, the feedback receiver 447 may be part of
the transmitter 412. The receiver 414 may be a primary receiver
(PRx) or a diversity receiver (DRx).
[0048] The transmitter 412 may receive a Tx inphase/quadrature
(I/Q) signal 426. The Tx inphase/quadrature (I/Q) signal 426 may be
passed through a Tx baseband filter (BBF) 424 before being
upconverted to a transmit frequency by an upconverter 422. The
transmit signal may then be amplified by a drive amplifier (DA) 420
before being transmitted. The transmitter 412 may include a phase
lock loop (PLL) 434, a Tx voltage controlled oscillator (VCO) 432
and a Div stage 430 that are used to generate a Tx local oscillator
(LO) signal 437. The Tx local oscillator (LO) signal 437 may be
provided to the upconverter 422.
[0049] The feedback receiver 447 may be used to regulate the
transmitter 412 (e.g., to provide periodic feedback about the power
levels of the transmitter 412 to ensure that the transmitter 412 is
transmitting with the proper amount of power). During regular
operation, the feedback receiver 447 may be off for considerable
amounts of time (to save power). In other words, the feedback
receiver 447 may normally be turned on for short amounts of time to
track the power of the transmitter 412 and then turned off Thus,
the circuitry in the feedback receiver 447 may be reused to tune a
notch filter 450. Tuning using the feedback receiver 447 may be
performed only one time or performed periodically, when the
feedback receiver 447 is idle.
[0050] The circuitry in the feedback receiver 447 may include a
feedback low noise amplifier (LNA) 436 that receives transmit
signals. The output of the feedback low noise amplifier (LNA) 436
may be coupled to a feedback downconverter 438 that reuses the
synthesizer of the transmitter 412. Thus, the feedback
downconverter 438 may receive the Tx local oscillator (LO) signal
437. The output of the feedback downconverter 438 may be coupled to
a feedback baseband filter (BBF) 442. The feedback baseband filter
(BBF) 442 may output the feedback inphase/quadrature (I/Q) signal
454 to the modem. The output of the feedback baseband filter (BBF)
442 may also be passed through an analog-to-digital converter (ADC)
444 before being provided to the modem.
[0051] To reuse the feedback receiver 447, the receiver 414 may
provide a feedback signal 443 to the feedback downconverter 438.
The feedback signal 443 may be current that is bled from a cascode
stage 448 in a Tx leakage signal reduction module 418. For example,
the cascode stage 448 may include a first amplifier 431a and a
second amplifier 431b. The output of the first amplifier 431a may
be provided to the feedback downconverter 438 as the feedback
signal 443. The output of the second amplifier 431b may be provided
to a downconverter 451 on the receiver 414 as the amplified receive
signal 449. The feedback signal 438 may provide feedback about a
notch filter 450 in the Tx leakage signal reduction module 418,
allowing the notch filter 450 to be tuned. The feedback signal 443
may be processed by the feedback receiver 447 (via the Rx
analog-to-digital converter (ADC) 444) to obtain a digital leakage
reduction signal 464. Additional digital signal processing (e.g.,
by the modem) may be performed on the output of the Rx
analog-to-digital converter (ADC) 444 to obtain the digital leakage
reduction signal 464. The digital leakage reduction signal 464 may
be used to tune the Tx leakage signal reduction module 418 in the
receiver 414.
[0052] The Tx leakage signal reduction module 418 may include a
notch filter 450. In one configuration, the notch filter 450 may
not be located on the transceiver chip 410 (and thus may be located
off-chip). The notch filter 450 may receive a receive signal 445.
The notch filter 450 may also receive the digital leakage reduction
signal 464 (which tunes the notch filter 450). The output of the
notch filter 450 may be provided to the cascode stage 448. As
discussed above, the cascode stage 448 may include a first
amplifier 431a and a second amplifier 431b. The output of the first
amplifier 431a may be the feedback signal 443 provided to the
feedback receiver 447. The output of the second amplifier 431b may
be the amplified receive signal 349 provided to the downconverter
451. In one configuration, 10% of the current in the cascode stage
448 may be bled as the feedback signal 443.
[0053] The digital leakage reduction signal 464 may provide
accurate notch filter 450 tuning across process, voltage and
temperature (PVT) to minimize the Tx leakage in the receive signal
445. The Tx leakage signal reduction module 418 may use existing
hardware (such as the feedback receiver 447) to reduce the Tx
leakage signal (by tuning the notch filter 450 to remove the Tx
leakage signal).
[0054] The receiver 414 may include a phase lock loop (PLL) 462, an
Rx voltage controlled oscillator (VCO) 460 and a Div stage 458 that
provide an Rx local oscillator (LO) signal 439 to the downconverter
451. The downconverter 451 may convert signals to baseband
frequency. The output of the downconverter 451 may be coupled to an
Rx baseband filter (BBF) 452. The Rx baseband filter (BBF) 452 may
then output the inphase/quadrature (I/Q) signal 456. Using the
feedback receiver 447 to tune the notch filter 450 may provide
reliable rejection of the Tx leakage signal across process, voltage
and temperature (PVT).
[0055] FIG. 5 is a flow diagram of another method 500 for
minimizing a Tx leakage signal in a receive signal 345. The method
500 may be performed by a wireless communication device 104. In one
configuration, the method 500 may be performed by a Tx leakage
signal reduction module 318 on a transceiver chip 310 in the
wireless communication device 104. The wireless communication
device 104 may receive 502 a receive signal 345. The receive signal
345 may be received by an antenna 106, 108. The receive signal 345
may include undesirable Tx leakage.
[0056] The wireless communication device 104 may pass 504 the
receive signal 345 through a notch filter 350. The wireless
communication device 104 may amplify 506 the receive signal using a
cascode stage 348. The wireless communication device 104 may
provide 508 a feedback signal 343 from the cascode stage 348 to a
feedback receiver 347. The wireless communication device 104 may
obtain 510 a digital leakage reduction signal 364 from the feedback
signal 343 using the feedback receiver 347. For example, the
feedback signal 343 may be downconverted by a feedback
downconverter 338, filtered by a feedback baseband filter (BBF) 342
and converted to a digital signal by an Rx analog-to-digital
converter (ADC) 344 in the feedback receiver 347.
[0057] The wireless communication device 104 may perform 512
process tuning on the notch filter 350 using the digital leakage
reduction signal 364 to minimize Tx leakage in the receive signal
345. For example, the digital leakage reduction signal 364 may be
used to adjust the values of the notch filter 350 (and thus adjust
the frequencies filtered by the notch filter 350).
[0058] FIG. 6 is a block diagram illustrating Tx leakage signal
reduction using an integrated duplexer. The integrated duplexer may
be implemented using a hybrid transformer 670. The hybrid
transformer 670 may include a first inductor L1 666a, a second
inductor L2 666b and a third inductor L3 666c. A coupling may occur
between the first inductor L1 666a, the second inductor L2 666b and
the third inductor L3 666c. The first inductor Ll 666a may be
coupled between a primary antenna 606 and the second inductor L2
666b. The second inductor L2 666b may be coupled between the first
inductor L1 666a and a balancing impedance ZL 668. The balancing
impedance ZL 668 may also be coupled to ground. The third inductor
L3 666c may be coupled to both a first differential input and a
second differential input of a low noise amplifier (LNA) 646 on a
transceiver chip 610. The low noise amplifier (LNA) 646 may be part
of a receiver 614.
[0059] The transceiver chip 610 of FIG. 6 may be one configuration
of the transceiver chip 110 of FIG. 1. The transceiver chip 610 may
include a transmitter 612, a feedback receiver 647 and the receiver
614. In one configuration, the feedback receiver 647 may be part of
the transmitter 612. The receiver 614 may be a primary receiver
(PRx) or a diversity receiver (DRx). The transmitter 612 may
receive a Tx inphase/quadrature (I/Q) signal 626. The Tx
inphase/quadrature (I/Q) signal 626 may be passed through a Tx
baseband filter (BBF) 624 before being upconverted to a transmit
frequency by an upconverter 622. The transmit signal may then be
amplified by a drive amplifier (DA) 620. The output of the drive
amplifier (DA) 620 may be coupled to the input of a power amplifier
(PA) 690. The power amplifier (PA) 690 may be located off the
transceiver chip 610. The output of the power amplifier (PA) 690
may be coupled between the first inductor L1 666a and the second
inductor L2 666b. The transmitter 612 may include a phase lock loop
(PLL) 634, a Tx voltage controlled oscillator (VCO) 632 and a Div
stage 630 that are used to generate a Tx local oscillator (LO)
signal 637. The Tx local oscillator (LO) signal 637 may be provided
to the upconverter 622.
[0060] The feedback receiver 647 may be used to regulate the
transmitter 612 (e.g., to provide periodic feedback about the power
levels of the transmitter 612 to ensure that the transmitter 612 is
transmitting with the proper amount of power). During regular
operation, the feedback receiver 647 may be off for considerable
amounts of time (to save power). In other words, the feedback
receiver 647 may normally be turned on for short amounts of time to
track the power of the transmitter 612 and then turned off. Thus,
the circuitry in the feedback receiver 647 may be reused to tune
the balancing impedance ZL 668. Tuning using the feedback receiver
447 may be performed only one time or performed periodically, when
the feedback receiver 447 is idle.
[0061] The circuitry in the feedback receiver 647 may include a
feedback low noise amplifier (LNA) 636 that receives transmit
signals. The output of the feedback low noise amplifier (LNA) 436
may be coupled to a feedback downconverter 438 that reuses the
synthesizer of the transmitter 412. Thus, the feedback
downconverter 638 may receive the Tx local oscillator (LO) signal
637. The output of the feedback downconverter 638 may be coupled to
a feedback baseband filter (BBF) 642. The feedback baseband filter
(BBF) 642 may output the feedback inphase/quadrature (I/Q) signal
654 to the modem. The output of the feedback baseband filter (BBF)
642 may also be passed through an analog-to-digital converter (ADC)
644 before being provided to the modem.
[0062] To reuse the feedback receiver 647, the receiver 614 may
provide a feedback signal 643 to the feedback downconverter 638.
The feedback signal 643 may be current that is bled from a cascode
stage 648 in the receiver 614. For example, the cascode stage 648
may include a first amplifier 631a and a second amplifier 631b. The
output of the first amplifier 631a may be provided to the feedback
downconverter 638 as the feedback signal 643. The output of the
second amplifier 631b may be provided to a downconverter 651 on the
receiver 614 as the amplified receive signal 649. The feedback
signal 638 may provide feedback about the balancing impedance ZL
668 in the hybrid transformer 670, allowing the balancing impedance
ZL 668 to be tuned. The feedback signal 643 may be processed by the
feedback receiver 647 (via the Rx analog-to-digital converter (ADC)
644) to obtain a digital leakage reduction signal 664. Additional
digital signal processing (e.g., by the modem) may be performed on
the output of the Rx analog-to-digital converter (ADC) 644 to
obtain the digital leakage reduction signal 664.
[0063] The digital leakage reduction signal 664 may be used to tune
the balancing impedance ZL 668 in the hybrid transformer 670. Using
the feedback receiver 647 to tune the balancing impedance ZL 668
may provide reliable rejection of the Tx leakage signal across
process, voltage and temperature (PVT). The impedance measured by
the primary antenna 606 may be too course for application in a
hybrid transformer 670. By using the balancing impedance ZL 668,
better sensitivity may be obtained. Continuous feedback (via the
digital leakage reduction signal 664) may be used to tune the
antenna load.
[0064] The output of the low noise amplifier (LNA) 646 may be
coupled to the input of the cascode stage 648. As discussed above,
the cascode stage 648 may include a first amplifier 631a and a
second amplifier 631b. The first amplifier 631a may output the
feedback signal 643 to the feedback receiver 647. The second
amplifier 631b may output the amplified receive signal 649 to a
downconverter 651 on the receiver 614. In one configuration, the
cascode stage 648 may bleed off 10% of the current to the feedback
receiver 647.
[0065] The receiver 614 may include a phase lock loop (PLL) 662, an
Rx voltage controlled oscillator (VCO) 660 and a Div stage 658 that
provide an Rx local oscillator (LO) signal 639 to the downconverter
651. The downconverter 651 may convert signals to baseband
frequency. The output of the downconverter 651 may be coupled to an
Rx baseband filter (BBF) 652. The Rx baseband filter (BBF) 652 may
then output the inphase/quadrature (I/Q) signal 656.
[0066] FIG. 7 is a circuit diagram illustrating a notch filter 750.
The notch filter 750 of FIG. 7 may be one configuration of the
notch filter 350 of FIG. 3 or the notch filter 450 of FIG. 4. The
notch filter 750 may have an input and an output. The notch filter
750 may include a first variable capacitor C1 770a and a second
variable capacitor C2 770b. The first variable capacitor C1 770a
may be coupled between the second variable capacitor C2 770b and
ground. The second variable capacitor C2 770b may be coupled to the
input of the notch filter 750.
[0067] The notch filter 750 may also include a resistor R1 774 and
an inductor L1 772. The resistor R1 774 may be coupled between the
inductor L1 772 and ground. The inductor L1 772 may be coupled
between the resistor R1 774 and the second variable capacitor C2
770b. The notch filter 750 may also include a resistor Rneg 776.
The resistor Rneg 776 may be coupled between ground and the second
variable capacitor C2 770b. The resistor Rneg 776 is the equivalent
negative resistor of a circuit (such as a negative-gm circuit) that
is used to improve the equivalent Quality factor (Q) of the
inductor L1 772. The Quality factor (Q) of the notch filter 750 may
be found using Equation (1):
Q = ( .omega. 0 L 1 R 1 ) . ( 1 ) ##EQU00001##
[0068] In Equation (1), .omega..sub.0 is the notch frequency of the
notch filter 750. The effective paddle inductance Lp from the
bottom of the capacitor C2 770b to ground may be found using
Equation (2):
L p = L 1 ( Q 2 + 1 Q 2 ) . ( 2 ) ##EQU00002##
[0069] The passband frequency f.sub.p of the notch filter 750 may
be found using Equation (3):
f p = 1 2 .pi. L p C 1 . ( 3 ) ##EQU00003##
[0070] The notch frequency f.sub.n of the notch filter 750 may be
found using Equation (4):
f n = 1 2 .pi. L p ( C 1 + C 2 ) . ( 4 ) ##EQU00004##
[0071] The value for the first variable capacitor C1 770a may be
found using Equation (5):
C 1 = 1 ( 2 .pi. f p ) 2 L p . ( 5 ) ##EQU00005##
[0072] Likewise, the value for the second variable capacitor C2
770b may be found using Equation (6):
C 2 = C 1 [ ( f p f n ) 2 - 1 ] . ( 6 ) ##EQU00006##
[0073] The equivalent resistance Rp from the capacitor C2 770b to
ground may be found using Equation (7):
R.sub.p=R.sub.1(Q.sup.2+1).parallel.R.sub.neg. (7)
[0074] The equivalent resistance Req may be found using Equation
(8):
R eq .apprxeq. R p ( 1 + C 1 C 2 ) 2 . ( 8 ) ##EQU00007##
[0075] FIG. 8 is a flow diagram of a method 800 for process tuning
a notch filter 750. The method 800 may be performed by a wireless
communication device 104. The wireless communication device 104 may
determine 802 a measured notch frequency. Determining the measured
notch frequency is discussed in additional detail below in relation
to FIG. 9. The measured notch frequency may be found using Equation
(9):
F n , meas = 1 2 .pi. L p ( 1 + .alpha. ) ( C 1 + C 2 ) . ( 9 )
##EQU00008##
[0076] In Equation (9), .alpha. is the process error that occurs
from the notch frequency shifting due to process error. The
wireless communication device 104 may determine 804 the process
error .alpha.. The process error a may be determined using Equation
(10:
.alpha. = [ ( f n f n , meas ) 2 - 1 ] . ( 10 ) ##EQU00009##
[0077] The wireless communication device 104 may calculate 806 a
first capacitor code (i.e., a code that adjusts the value of the
first variable capacitor Cl 770a) and a second capacitor code
(i.e., a code that adjusts the value of the second variable
capacitor C2 770b) that meets the C.sub.1.sub.--.sub.aim and
C.sub.2.sub.--.sub.aim for a given channel. The wireless
communication device 104 may then apply 808 the first capacitor
code and the second capacitor code to the notch filter 750.
[0078] FIG. 9 is a flow diagram of a method 900 for finding the
measured notch frequency of a notch filter 750. The method 900 may
be performed by a wireless communication device 104. Notch tuning
may be performed with any search-efficient algorithm, such as a
gradient search algorithm. The wireless communication device 104
may apply 902 a transmit tone on three different frequencies to the
notch filter 750. The wireless communication device 104 may then
measure 904 the DC gain through the feedback receiver 347. The
wireless communication device 104 may calculate 906 the gradient.
The wireless communication device 104 may determine 908 a notch
frequency using a gradient search algorithm. The notch frequency
found using the gradient search algorithm may have better results
than a linear search. The steps in the method 900 may need to be
repeated to precisely locate the notch frequency and fine tune the
notch filter 750.
[0079] FIG. 10 illustrates certain components that may be included
within a wireless communication device 1004. The wireless
communication device 1004 may be an access terminal, a mobile
station, a user equipment (UE), etc. The wireless communication
device 1004 includes a processor 1003. The processor 1003 may be a
general purpose single- or multi-chip microprocessor (e.g., an
ARM), a special purpose microprocessor (e.g., a digital signal
processor (DSP)), a microcontroller, a programmable gate array,
etc. The processor 1003 may be referred to as a central processing
unit (CPU). Although just a single processor 1003 is shown in the
wireless communication device 1004 of FIG. 10, in an alternative
configuration, a combination of processors (e.g., an ARM and DSP)
could be used.
[0080] The wireless communication device 1004 also includes memory
1005. The memory 1005 may be any electronic component capable of
storing electronic information. The memory 1005 may be embodied as
random access memory (RAM), read-only memory (ROM), magnetic disk
storage media, optical storage media, flash memory devices in RAM,
on-board memory included with the processor, EPROM memory, EEPROM
memory, registers and so forth, including combinations thereof
[0081] Data 1007a and instructions 1009a may be stored in the
memory 1005. The instructions 1009a may be executable by the
processor 1003 to implement the methods disclosed herein. Executing
the instructions 1009a may involve the use of the data 1007a that
is stored in the memory 1005. When the processor 1003 executes the
instructions 1009, various portions of the instructions 1009b may
be loaded onto the processor 1003, and various pieces of data 1007b
may be loaded onto the processor 1003.
[0082] The wireless communication device 1004 may also include a
transmitter 1011 and a receiver 1013 to allow transmission and
reception of signals to and from the wireless communication device
1004 via a first antenna 1017a and a second antenna 1017b. The
transmitter 1011 and receiver 1013 may be collectively referred to
as a transceiver 1015. The wireless communication device 1004 may
also include (not shown) multiple transmitters, additional
antennas, multiple receivers and/or multiple transceivers.
[0083] The wireless communication device 1004 may include a digital
signal processor (DSP) 1021. The wireless communication device 1004
may also include a communications interface 1023. The
communications interface 1023 may allow a user to interact with the
wireless communication device 1004.
[0084] The various components of the wireless communication device
1004 may be coupled together by one or more buses, which may
include a power bus, a control signal bus, a status signal bus, a
data bus, etc. For the sake of clarity, the various buses are
illustrated in FIG. 10 as a bus system 1019.
[0085] The term "determining" encompasses a wide variety of actions
and, therefore, "determining" can include calculating, computing,
processing, deriving, investigating, looking up (e.g., looking up
in a table, a database or another data structure), ascertaining and
the like. Also, "determining" can include receiving (e.g.,
receiving information), accessing (e.g., accessing data in a
memory) and the like. Also, "determining" can include resolving,
selecting, choosing, establishing and the like.
[0086] The phrase "based on" does not mean "based only on," unless
expressly specified otherwise. In other words, the phrase "based
on" describes both "based only on" and "based at least on."
[0087] The term "processor" should be interpreted broadly to
encompass a general purpose processor, a central processing unit
(CPU), a microprocessor, a digital signal processor (DSP), a
controller, a microcontroller, a state machine and so forth. Under
some circumstances, a "processor" may refer to an application
specific integrated circuit (ASIC), a programmable logic device
(PLD), a field programmable gate array (FPGA), etc. The term
"processor" may refer to a combination of processing devices, e.g.,
a combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0088] The term "memory" should be interpreted broadly to encompass
any electronic component capable of storing electronic information.
The term memory may refer to various types of processor-readable
media such as random access memory (RAM), read-only memory (ROM),
non-volatile random access memory (NVRAM), programmable read-only
memory (PROM), erasable programmable read-only memory (EPROM),
electrically erasable PROM (EEPROM), flash memory, magnetic or
optical data storage, registers, etc. Memory is said to be in
electronic communication with a processor if the processor can read
information from and/or write information to the memory. Memory
that is integral to a processor is in electronic communication with
the processor.
[0089] The terms "instructions" and "code" should be interpreted
broadly to include any type of computer-readable statement(s). For
example, the terms "instructions" and "code" may refer to one or
more programs, routines, sub-routines, functions, procedures, etc.
"Instructions" and "code" may comprise a single computer-readable
statement or many computer-readable statements.
[0090] The functions described herein may be implemented in
software or firmware being executed by hardware. The functions may
be stored as one or more instructions on a computer-readable
medium. The terms "computer-readable medium" or "computer-program
product" refers to any tangible storage medium that can be accessed
by a computer or a processor. By way of example, and not
limitation, a computer-readable medium may comprise RAM, ROM,
EEPROM, CD-ROM or other optical disk storage, magnetic disk storage
or other magnetic storage devices, or any other medium that can be
used to carry or store desired program code in the form of
instructions or data structures and that can be accessed by a
computer. Disk and disc, as used herein, includes compact disc
(CD), laser disc, optical disc, digital versatile disc (DVD),
floppy disk and Blu-ray.RTM. disc where disks usually reproduce
data magnetically, while discs reproduce data optically with
lasers. It should be noted that a computer-readable medium may be
tangible and non-transitory. The term "computer-program product"
refers to a computing device or processor in combination with code
or instructions (e.g., a "program") that may be executed, processed
or computed by the computing device or processor. As used herein,
the term "code" may refer to software, instructions, code or data
that is/are executable by a computing device or processor.
[0091] Software or instructions may also be transmitted over a
transmission medium. For example, if the software is transmitted
from a website, server, or other remote source using a coaxial
cable, fiber optic cable, twisted pair, digital subscriber line
(DSL), or wireless technologies such as infrared, radio and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio and microwave
are included in the definition of transmission medium.
[0092] The methods disclosed herein comprise one or more steps or
actions for achieving the described method. The method steps and/or
actions may be interchanged with one another without departing from
the scope of the claims. In other words, unless a specific order of
steps or actions is required for proper operation of the method
that is being described, the order and/or use of specific steps
and/or actions may be modified without departing from the scope of
the claims.
[0093] Further, it should be appreciated that modules and/or other
appropriate means for performing the methods and techniques
described herein, such as those illustrated by FIGS. 2, 5, 8 and 9,
can be downloaded and/or otherwise obtained by a device. For
example, a device may be coupled to a server to facilitate the
transfer of means for performing the methods described herein.
Alternatively, various methods described herein can be provided via
a storage means (e.g., random access memory (RAM), read-only memory
(ROM), a physical storage medium such as a compact disc (CD) or
floppy disk, etc.), such that a device may obtain the various
methods upon coupling or providing the storage means to the device.
Moreover, any other suitable technique for providing the methods
and techniques described herein to a device can be utilized.
[0094] It is to be understood that the claims are not limited to
the precise configuration and components illustrated above. Various
modifications, changes and variations may be made in the
arrangement, operation and details of the systems, methods and
apparatus described herein without departing from the scope of the
claims.
* * * * *