U.S. patent application number 15/432885 was filed with the patent office on 2018-01-11 for wireless transceiver apparatus and method capable of controlling gain(s) of amplifier(s) by detecting power of interference signal in the air with considerations of power saving and smaller circuit area.
The applicant listed for this patent is PixArt Imaging Inc.. Invention is credited to Peng-Sen Chen.
Application Number | 20180014266 15/432885 |
Document ID | / |
Family ID | 60893205 |
Filed Date | 2018-01-11 |
United States Patent
Application |
20180014266 |
Kind Code |
A1 |
Chen; Peng-Sen |
January 11, 2018 |
WIRELESS TRANSCEIVER APPARATUS AND METHOD CAPABLE OF CONTROLLING
GAIN(S) OF AMPLIFIER(S) BY DETECTING POWER OF INTERFERENCE SIGNAL
IN THE AIR WITH CONSIDERATIONS OF POWER SAVING AND SMALLER CIRCUIT
AREA
Abstract
A wireless transceiver apparatus includes a power detector, an
analog signal receiving circuit at wireless signal reception side,
and a processing circuit. The power detector is configured at
wireless signal transmission side and used for detecting power of a
power amplifier on a transmitting path of wireless signal
transmission side. The analog signal receiving circuit is couple to
the power detector and used for receiving a wireless signal form an
antenna. Under signal reception mode, the analog signal receiving
circuit transmits the received wireless signal to the processing
circuit. Under interference detection mode, the analog signal
receiving circuit transfers the received wireless signal (as
interference) to the power detector, and the power detector is used
for detecting the power of wireless signal to measure an
interference power value and transmit the value to the processing
circuit.
Inventors: |
Chen; Peng-Sen; (Hsin-Chu
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PixArt Imaging Inc. |
Hsin-Chu City |
|
TW |
|
|
Family ID: |
60893205 |
Appl. No.: |
15/432885 |
Filed: |
February 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02D 30/70 20200801;
H04B 17/13 20150115; H04W 4/80 20180201; H04W 52/52 20130101 |
International
Class: |
H04W 52/52 20090101
H04W052/52; H04W 4/00 20090101 H04W004/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2016 |
TW |
105121784 |
Claims
1. A wireless transceiver apparatus, comprising: a power detector,
configured at a wireless signal transmission side and used for
detecting power of a power amplifier on a transmitting path of the
wireless signal transmission side; an analog signal receiving
circuit, configured at a wireless signal reception side and coupled
to the power detector, the analog signal receiving circuit
receiving a wireless signal form an antenna; and a processing
circuit, coupled to the analog signal receiving circuit; wherein,
under a signal reception mode, the analog signal receiving circuit
transmits the received wireless signal to the processing circuit;
under an interference detection mode, the analog signal receiving
circuit transfers the received wireless signal to the power
detector, and the power detector detects a power of the received
wireless signal to measure an interference power value and transmit
the interference power value to the processing circuit.
2. The wireless transceiver apparatus of claim 1, wherein the
processing circuit is used for converting the interference power
value to a digital value and controlling a gain value of at least
one amplifier of the analog signal receiving circuit according to
the digital value.
3. The wireless transceiver apparatus of claim 2, wherein when the
digital value is greater than a first threshold value, the
processing circuit is arranged to control and determine the gain
value of the at least one amplifier as a first gain value; and,
when the digital value is greater than a second threshold, the
processing circuit is arranged to control and determine the gain
value of the at least one amplifier as a second gain value to
reduce interference wherein the second threshold value is higher
than the first threshold value and the second gain value is smaller
than the first gain value.
4. The wireless transceiver apparatus of claim 2, wherein the
analog signal receiving circuit comprises: a first amplifier,
coupled to the antenna; a mixer, coupled to the first amplifier; a
band-pass filter, coupled to the mixer; a second amplifier, coupled
to the band-pass filter; wherein the processing circuit
respectively controls a gain value of the first amplifier and a
gain value of the second amplifier according to the digital
value.
5. The wireless transceiver apparatus of claim 4, further
comprising: a first switch, disposed between the first amplifier
and the mixer; a second switch, disposed between the analog signal
receiving circuit and the power detector; a third switch, disposed
between the power detector and the power amplifier on the
transmitting path; and a fourth switch, disposed between the analog
signal receiving circuit and the processing circuit; wherein under
the signal reception mode, the processing circuit controls states
of the first switch, the third switch, and the fourth switch become
closed respectively; and under the power detection mode, the
processing circuit controls the states of the first switch, the
third switch, and the fourth switch become open respectively and
controls a state of the second switch become closed.
6. The wireless transceiver apparatus of claim 1, wherein the
wireless transceiver apparatus includes a Bluetooth communication
capability, and under the signal reception mode the wireless
transceiver apparatus is arranged to receive Bluetooth data
packet(s) and is arranged to enable and enter the interference
detection mode when is not arranged to receive the Bluetooth data
packet(s).
7. The wireless transceiver apparatus of claim 6, wherein the
wireless transceiver apparatus is arranged to enable and enter the
interference detection mode before receiving a preamble signal of
Bluetooth communication, or the wireless transceiver apparatus is
arranged to enable and enter the interference detection mode after
completely receiving one Bluetooth data packet.
8. A method used for a wireless transceiver apparatus, comprising:
providing a power detector configured at a wireless signal
transmission side; providing an analog signal receiving circuit
configured at a wireless signal reception side, the analog signal
receiving circuit receiving a wireless signal form an antenna;
under a signal reception mode, utilizing the analog signal
receiving circuit to transmit the received wireless signal to a
processing circuit; and under an interference detection mode:
transferring the received wireless signal from the analog signal
receiving circuit to the power detector; and utilizing the power
detector to detect a power of the received wireless signal to
measure an interference power value and transmit the interference
power value to the processing circuit.
9. The method of claim 8, further comprising: converting the
interference power value to a digital value; and controlling a gain
value of at least one amplifier of the analog signal receiving
circuit according to the digital value.
10. The method of claim 9, wherein the step of controlling the gain
value of the at least one amplifier of the analog signal receiving
circuit according to the digital value comprises: controlling and
determining the gain value of the at least one amplifier as a first
gain value when the digital value is greater than a first threshold
value; and controlling and determining the gain value of the at
least one amplifier as a second gain value to reduce interference
when the digital value is greater than a second threshold; wherein
the second threshold value is higher than the first threshold value
and the second gain value is smaller than the first gain value.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates to a wireless transceiver scheme, and
more particularly to a wireless transceiver apparatus and
corresponding method.
2. Description of the Prior Art
[0002] Generally speaking, conventional wireless transceivers based
on Bluetooth communication standard suffer from the interference of
Wi-Fi signals especially when the signal power of Bluetooth
communication is smaller than that of Wi-Fi signals. For amplifiers
such as low-noise amplifier (LNA) at the wireless signal reception
side of the conventional Bluetooth communication transceivers, the
interference of Wi-Fi signals usually cause signal saturation for
the amplifiers since the amplifiers are designed to be more
sensitive and with higher gain values. Thus, even though partial
Wi-Fi signal interference can be filtered out by using filter (s)
at the post-stage circuit, however, the signal saturation
inevitably causes the poor quality for signal reception. The
interference of Wi-Fi signals will not always exist, continuously
and always enabling the detection for the interference will
inevitably need additional circuit element(s) for detection and
also consume more power. Using additional circuit element(s) for
detection often means that further circuit area is needed and
configured to implement the additional circuit element (s). it is
difficult to design an interference detection scheme for Bluetooth
transceiver(s) with the advantage of power saving.
SUMMARY OF THE INVENTION
[0003] Therefore one of the objectives of the invention is to
provide a wireless transceiver apparatus and method applied for the
wireless transceiver apparatus, to solve the above-mentioned
problems.
[0004] According to embodiment of the invention, a wireless
transceiver apparatus is disclosed. The wireless transceiver
apparatus comprises a power detector, an analog signal receiving
circuit, and a processing circuit. The power detector is configured
at a wireless signal transmission side and used for detecting power
of a power amplifier on a transmitting path of the wireless signal
transmission side. The analog signal receiving circuit is
configured at a wireless signal reception side and coupled to the
power detector, and is used for receiving a wireless signal form an
antenna. The processing circuit is coupled to the analog signal
receiving circuit. Under a signal reception mode, the analog signal
receiving circuit transmits the received wireless signal to the
processing circuit. Under an interference detection mode, the
analog signal receiving circuit transfers the received wireless
signal to the power detector, and the power detector detects a
power of the received wireless signal to measure an interference
power value and transmit the interference power value to the
processing circuit.
[0005] According to the embodiments, a method used for a wireless
transceiver apparatus is disclosed. The method comprises: providing
a power detector configured at a wireless signal transmission side;
providing an analog signal receiving circuit configured at a
wireless signal reception side, the analog signal receiving circuit
receiving a wireless signal form an antenna; under a signal
reception mode, utilizing the analog signal receiving circuit to
transmit the received wireless signal to a processing circuit; and,
under an interference detection mode: transferring the received
wireless signal from the analog signal receiving circuit to the
power detector; and utilizing the power detector to detect a power
of the received wireless signal to measure an interference power
value and transmit the interference power value to the processing
circuit.
[0006] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is block diagram of a wireless transceiver apparatus
according to an embodiment of the invention.
[0008] FIG. 2 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus of FIG. 1 when operating
under the power calibration mode.
[0009] FIG. 3 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus of FIG. 1 when operating
under the interference detection mode.
[0010] FIG. 4 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus of FIG. 1 when operating
under the signal reception mode.
DETAILED DESCRIPTION
[0011] FIG. 1 is block diagram of a wireless transceiver apparatus
100 according to an embodiment of the invention. The wireless
transceiver apparatus 100 comprises a wireless signal transmission
side and a wireless signal reception side, and is used for
transmitting a wireless signal and receiving a wireless signal,
respectively. The wireless transceiver apparatus 100 can be applied
to Bluetooth communication and includes a Bluetooth communication
capability for receiving and sending a Bluetooth wireless
communication signal (but not limited).
[0012] Bluetooth communication standard for example employs the
frequency band of 2.4 GHz, and an adjacent frequency band for
example is used by other communication standard such as Wi-Fi
communication standard. The performance of a conventional wireless
transceiver for Bluetooth communication is easily affected or
influenced by Wi-Fi communication signals especially when the
signal power of Bluetooth communication signal is smaller than the
signal power of Wi-Fi communication signals. A low-noise amplifier
(LNA) configured at the wireless signal reception side of the
conventional transceiver for Bluetooth communication is usually
designed with higher sensitivity for processing the signal and
designed with a greater gain value. The LNA of the conventional
transceiver usually and easily suffers from signal saturation
resulted from the interference of Wi-Fi communication signals at
adjacent frequency bands. A conventional scheme may employ a filter
at a post-stage circuit to filter out partial interference
generated from the Wi-Fi communication signals. However, the signal
saturation for the LNA inevitably causes the poor quality for
signal reception. Since the Wi-Fi communication signals may not
always exist, continually and always detecting the interference of
Wi-Fi signals would consume much power, and also needs an
additional circuit for detection and thus more circuit areas are
required to implement the additional circuit. It becomes more
difficult to design a scheme for detection the interference
source.
[0013] To solve the above-mentioned problems, the wireless
transceiver apparatus 100 of the embodiment is arranged to perform
interference detection operation by using partial circuit(s) on a
transmitting path at the wireless signal transmission side and/or
is arranged to execute the interference detection operation at a
specific timing designed based on Bluetooth communication standard.
The partial circuit(s) is/are shared for signal transmission and
interference detection. The wireless transceiver apparatus 100 can
appropriately detect energy/power of the interference of other
wireless signals in the air to avoid signal saturation introduced
to an LNA of the front-end circuit and/or signal saturation for
amplifier(s) of the post-stage circuit, with consideration of power
saving and without occupying additional circuit areas (or without
adding other circuit elements) at the same time.
[0014] The wireless transceiver apparatus 100 performs interference
detection operation by using partial circuit element(s) on the
transmitting path at the wireless signal transmission side. For
example, the wireless transceiver apparatus 100 employs at least a
power detector, which is disposed on the transmitting path of the
wireless signal transmission side and configured for performing
power calibration upon a signal at the transmission side, to
perform the interference detection operation. For signal
transmission, the power detector is used for performing power
calibration to maintain a wireless signal, to be transmitted to the
air, at the same level. For interference detection, the power
detector is used for detecting whether interference of other
wireless signal exists and the power/energy of the interference.
Since the power detector on the transmitting path at the
transmission side is further employed to the perform interference
detection operation, this would not need to implement more
additional circuits to occupy additional circuit areas. Even
additional detection circuits are not required.
[0015] Taking examples of Bluetooth communication application, the
wireless transceiver apparatus 100 is arranged to activate/enable
and enter the interference detection mode when is not arranged to
receive Bluetooth data packet(s). For Bluetooth communication, a
preparation time period (about 80-90 microseconds but not limited)
is used for signal reception preparation before a Bluetooth data
packet is received. The preparation time period for example is
designed as a period before a preamble signal of the Bluetooth data
packet is received. The wireless transceiver apparatus 100 is
arranged to select this preparation time period as one of the
periods/timings which can be used for performing the interference
detection operation. The wireless transceiver apparatus 100 is
capable of detecting whether the interference of Wi-Fi signal
exists or not before receiving one Bluetooth data packet. In
practice, the wireless transceiver apparatus 100 needs only 15
microseconds (but not limited) to perform the interference
detection operation, so the reception of Bluetooth data packet(s)
is not affected by the interference detection operation.
Additionally, the wireless transceiver apparatus 100 can be
arranged to activate/enable the interference detection mode and
enter the interference detection mode to perform the interference
detection operation when determining that a Bluetooth data packet
has been lost, determining that the packet error rate becomes much
higher abnormally, or when one Bluetooth data packet has been
received successfully. Compared to the conventional scheme
continuously detecting the interference of Wi-Fi signals, the
wireless transceiver apparatus 100 of this embodiment can save more
power. It is suitable to apply the wireless transceiver apparatus
100 to a portable electronic device such as a wearable electronic
device. Further, it should be noted that the above mentioned
timings/periods used for performing interference detection
operation are merely used for illustrative purposes but not meant
to be limitations of the invention. The interference detection
operation can be performed at different timings or performed during
different periods in a Bluetooth communication system.
[0016] Refer back to FIG. 1. In practice, the wireless transceiver
apparatus 100 includes a transmitting circuit 101T on a signal
transmitting path at the wireless signal transmission side, an
analog signal receiving circuit 101R on a signal receiving path at
the wireless signal reception side, an antenna unit 102, and a
processing circuit 103. The transmitting circuit 101T includes a
digital-to-analog converter (DAC) 105, a low-pass filter (LPF) 110,
a mixer 115 connected to a local oscillation signal LO, a power
amplifier 120, a transducer 125, and a power detector 130. The
analog signal receiving circuit 101R includes an amplifier 140 such
as a low noise amplifier (LNA), a transducer 145, a mixer 150, a
band-pass filter (BPF) 155, and an amplifier 160. The antenna unit
1002 is used for sending and receiving wireless signals via
Bluetooth communication standard. The processing circuit 103
includes a multiplexer 165, an analog-to-digital converter (ADC)
170, and a signal processing circuit 175 wherein the signal
processing circuit 175 can be a baseband control circuit or a
digital signal processing circuit. In addition, the wireless
transceiver apparatus 100 further comprises four switch elements
SW1-SW4. The switch element SW1 is selectively coupled between an
output of the transducer 145 and an input of the mixer 150. The
switch element SW2 is selectively coupled between the output of the
transducer 145 and an input of the power detector 130. The switch
element SW3 is selectively coupled between the output of the
transducer 145 and another input of the power detector 130. The
switch element SW4 is selectively coupled between the output of the
amplifier 160 and the input of the multiplexer 165. The state (open
or short) of each switch element SW1-SW4 can be controlled by the
signal processing circuit 175 within the processing circuit 103,
and each switch element SW1-SW4 can be respectively turned on to
become short or turned off to become open in response to different
operations of the wireless transceiver apparatus 100. The
electrical connections between other circuit elements are
illustrated on FIG. 1.
[0017] FIG. 2 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus 100 of FIG. 1 operating under
the power calibration mode. When the wireless transceiver apparatus
100 enters the power calibration mode, the signal processing
circuit 175 is arranged to control the switch elements SW1, SW2,
and SW4 to become open and control the switch element SW3 to become
short. The multiplexer 165 of processing circuit 103 is arranged to
select the output signal of the power detector 130 as its output.
As indicated by arrows shown in FIG. 2, the transmission signal ST
passes through the DAC 105, LPF 110, mixer 115, power amplifier
120, transducer 125, power detector 130, multiplexer 165, and the
ADC 170, and is processed by these circuit elements correspondingly
and finally transmitted to the signal processing circuit 175. The
power detector 130 is used for performing power detection upon the
transmission signal ST to detect the signal power of power
amplifier 120 on the transmitting path at the wireless signal
transmission side. The signal processing circuit 175 can control
the power amplifier 120 to perform the power calibration according
to the detection result generated by the power detector 130, to
maintain the power of the wireless transmission signal to be
transmitted to the air at the same level substantially.
[0018] FIG. 3 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus 100 of FIG. 1 operating under
the interference detection mode. As shown in FIG. 3, when the
wireless transceiver apparatus 100 enters the interference
detection mode, the signal processing circuit 175 is arranged to
control the switch elements SW1, SW3, and SW4 to become open and
control the switch element SW2 to become short. The multiplexer 165
of processing circuit 103 selects the output signal of power
detector 130 as its output. Under the interference detection mode,
the wireless signal SR detected by the wireless transceiver
apparatus 100 is regarded as an interference signal rather than a
data signal or a data packet. As indicated by arrows shown in FIG.
3, if the interference of Wi-Fi signals exists, then the signal
interference will be received by the antenna unit 102 and
transmitted through the amplifier 140, transducer 145, power
detector 130, multiplexer 165, ADC 170, and finally transmitted to
the signal processing circuit 175. That is, the analog signal
receiving circuit 101R is arranged to transfer the received
wireless signal (i.e. the Wi-Fi signal) to the power detector 130,
and the received wireless signal (Wi-Fi signal) does not pass
through the mixer 150, BPF 155, and the amplifier 160. The power
detector 130 performs power detection for the energy or power of
Wi-Fi signal interference, to detect the power of Wi-Fi signal
interference, measure an interference power value, and transmit the
interference power value to the processing circuit 103. The ADC 170
of processing circuit 103 is arranged to convert the interference
power value into a digital value, and the signal processing circuit
175 is arranged to adaptively control the gain value of at least
one amplifier in the amplifiers 140 and 160 within the analog
signal receiving circuit 101R according to the digital value under
the signal reception mode, to avoid signal saturation.
[0019] FIG. 4 is a diagram illustrating the signal processing flow
of the wireless transceiver apparatus 100 of FIG. 1 operating under
the signal reception mode. The signal processing circuit 175 is
arranged to control the switch elements SW2 and SW3 to become open
and control the switch elements SW1 and SW4 to become short. The
multiplexer 165 of processing circuit 103 is arranged to select the
output signal of the amplifier 160 as its output. Under the signal
reception mode, the wireless signal SR detected by the wireless
transceiver apparatus 100 is regarded as a dada signal or a data
packet. As indicated by arrows shown in FIG. 4, the wireless signal
SR transmitted with Bluetooth communication standard is received by
the antenna unit 102 and then is transmitted and received by the
analog signal receiving circuit 101R. The wireless signal SR is
sequentially transmitted through the amplifier 140, transducer 145,
mixer 150, BPF 155, amplifier 160, multiplexer 165, ADC 170, and
finally transmitted to the signal processing circuit 175. When the
wireless transceiver apparatus 100 enters the analog reception mode
to receive Bluetooth data packet(s), the signal processing circuit
175 can adaptively control the gain value of at least one amplifier
in the amplifiers 140 and 160 within the analog signal receiving
circuit 101R according to the interference detection result
generated by the power detector 130, to avoid signal saturation. In
practice, when the digital value is higher than a first threshold
value, the signal processing circuit 175 can control the gain value
of at least one amplifier as a first gain value. When the digital
value is higher than a second threshold value, the signal
processing circuit 175 can control the gain value of the at least
one amplifier as a second gain value. By doing this, the
interference of other signal sources can be reduced. The second
threshold value is higher than the first threshold value, and the
second gain value is smaller than the first gain value. The
above-mentioned scheme for adjusting the gain value based on the
threshold values is one embodiment for illustrative purposes. In
other embodiments, a single threshold value can be used for
deciding and adjusting the gain value(s) of the amplifier(s). For
example, when the digital value is higher than the single threshold
value, the gain value of an amplifier is decreased; instead, when
the digital value is lower than the single threshold value, the
gain value is increased.
[0020] It should be noted that the invention aims at utilizing at
least the power detector, which is at the wireless signal
transmission side and used for power calibration for the
transmission signal, to perform interference detection operation.
In other embodiments, the arrangement positions of switch elements
SW1-SW3 can be adjusted and changed to further utilize the
transducer 125 to perform interference detection operation. In
practice, the arrangement position of switch element SW1 can be
changed to be coupled between the output of the amplifier 140 and
the input of the transducer 145. The arrangement position of switch
element SW2 can be changed to be coupled between the output of the
amplifier 140 and the input of the transducer 125. The arrangement
position of switch element SW3 can be changed to be coupled between
the output of the power amplifier 120 and the input of the
transducer 125. The control of the corresponding switch elements is
identical to that of switch elements as shown in FIG. 1, and is not
detailed for brevity. Further, in another embodiment, the analog
signal receiving circuit 101R can be configured to include the LNA
140 and exclude the amplifier 160. The operation of controlling the
gain value (s) of amplifier (s) to avoid signal saturation resulted
from other interference signals can comprise the operation of
controlling the gain value of merely a single one amplifier within
the analog signal receiving circuit 101R and/or the operation of
controlling the gain values of two or more amplifiers. This also
obeys the spirit of the invention.
[0021] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *