Patent Description:
Because of the progress in communication technology, the requirement of the bandwidth in the wireless communication is increasing gradually. In the traditional listen-before-talk wireless communication mechanism, in order to share spectrum resources, the receiving device may confirm whether there is any other user using the channel which the receiving device is using first, and then perform data transmission and reception. However, in the complicated communication environment, the frequency band that the receiving device is using may be affected by the signals in the adjacent frequency band (i.e. the signals in the adjacent frequency band may leak into the frequency band that the receiving device is using). As a result, communication may be interrupted.

Traditionally, a band-pass filter in the receiving device may be used to filter out the signals in the adjacent frequency band. However, the traditional scheme does not consider the signals leaking into the used frequency band from the adjacent frequency band. Therefore, the receiving device cannot determine whether there is any leaking signal in the used frequency band from the adjacent frequency band, and cannot determine the influence level of the leaking signals on the in-band signals. Therefore, the receiving device cannot perform the appropriate adjustment in response to the leaking signals from the adjacent frequency band for the in-band signals.

<CIT> discloses a cellular telephone (mobile station) including a variable attenuator circuit, wherein an antenna connected to a duplexer are both connected as part of a cellular receiver section. <CIT> discloses a receiver with dual-mode automatic gain control. <CIT> discloses a method for digital cancellation of interference of a transmit signal.

Independent claim <NUM> defines a receiving device and corresponding independent claim <NUM> defines a method for dynamically adjusting the attenuation value of a received signal to overcome the aforementioned problems.

The following further embodiments refer to subject-matter introduced by the independent claims <NUM> and <NUM>.

In some embodiments of the invention, the processor determines whether the signal level of the out-band signal is greater than a first threshold, and whether the signal quality of the in-band signal is greater than a second threshold.

In some embodiments of the invention, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor commands the adjustable attenuator to increase the attenuation value.

In some embodiments of the invention, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor commands the adjustable attenuator to decrease the attenuation value, wherein if the attenuation value has been adjusted to a lower limit value, the processor commands the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power.

In some embodiments of the invention, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor commands the adjustable attenuator to increase the attenuation value.

In some embodiments of the invention, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor commands the adjustable attenuator to decrease the attenuation value, wherein if the attenuation value has been adjusted to a lower limit value, the processor commands the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power.

In some embodiments of the invention, when the signal quality of the in-band signal is not greater than the second threshold, the processor commands the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power.

In some embodiments of the invention, before the processor determines whether the signal level of the out-band signal is greater than the first threshold and whether the signal quality of the in-band signal is greater than the second threshold, the processor determines whether the packet error rate of the received signal is lower than a threshold.

In some embodiments of the invention, the filter circuit is a notch filter, wherein the out-band signal is reflected to the circulator from the notch filter and the in-band signal passes through the notch filter. In some embodiments of the invention, the filter circuit is a band-pass filter, wherein the in-band signal is reflected to the circulator from the band-pass filter and the out-band signal passes through the band-pass filter.

An embodiment of the invention provides a method according to independent claim <NUM>.

In an embodiment of the method, the method further comprises: adjusting, by the adjustable attenuator, the attenuation value corresponding to the in-band signal. In an embodiment of the method, the method further comprises: determining, by the processor, whether a signal level of the out-band signal is greater than a first threshold. In an embodiment of the method, the method further comprises: determining, by the processor, whether a signal quality of the in-band signal is greater than a second threshold. In an embodiment of the method, the method further comprises: when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, commanding, by the processor, the adjustable attenuator to increase the attenuation value. In an embodiment of the method, the method further comprises: when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, commanding, by the processor, the adjustable attenuator to decrease the attenuation value, wherein, if the attenuation value has been adjusted to a lower limit value, the processor commands the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power. In an embodiment of the method, the method further comprises: when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, commanding, by the processor, the adjustable attenuator to increase the attenuation value. In an embodiment of the method, the method further comprises: when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, commanding, by the processor, the adjustable attenuator to decrease the attenuation value, wherein if the attenuation value has been adjusted to a lower limit value, the processor commands the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power. In an embodiment of the method, the method further comprises: when the signal quality of the in-band signal is not greater than the second threshold, commanding, by the processor, the transceiver to transmit a request packet to a transmitting device to ask the transmitting device to adjust its transmission power. In an embodiment of the method, the method further comprises: before the processor determines that the signal level of the out-band signal is greater than the first threshold and determines that the signal quality of the in-band signal is greater than the second threshold, determining, by the processor, whether a packet error rate of the received signal is lower than a threshold. In an embodiment of the method, the filter circuit is a notch filter, wherein the out-band signal is reflected to the circulator from the notch filter and the in-band signal passes through the notch filter. In an embodiment of the method, the filter circuit is a band-pass filter, wherein the in-band signal is reflected to the circulator from the band-pass filter and the out-band signal passes through the band-pass filter.

Other aspects and features of the invention will become apparent to those with ordinary skill in the art upon review of the following descriptions of specific embodiments of receiving device and method for dynamically adjusting the attenuation value of a received signal.

The invention will become more fully understood by referring to the following detailed description with reference to the accompanying drawings, wherein:.

<FIG> is a block diagram of a receiving device <NUM> according to an embodiment of the invention. As shown in <FIG>, the receiving device <NUM> comprises an antenna device <NUM>, a circulator <NUM>, notch filter (or band-stop filter) <NUM>, a transceiver <NUM>, a processor <NUM>, an adjustable attenuator <NUM>, and switch circuit <NUM>. It should be noted that the block diagram shown in <FIG> is only used to illustrate the embodiments of the invention, but the invention should not be limited thereto. The receiving device <NUM> may comprise other elements. For example, the receiving device <NUM> may comprise a radio frequency (RF) signal processing circuit and a base band (BS) signal processing circuit. In additional, the circulator <NUM>, notch filter <NUM>, processor <NUM> and an adjustable attenuator <NUM> can be integrated into a chip or a communication module.

According to the embodiments of the invention, the receiving device <NUM> can be applied to the listen-before-talk wireless communication mechanism, such as Wi-Fi, and other wireless communication technologies. In addition, according to embodiments of the invention, the receiving device <NUM> may belong to and configured in an electronic device, e.g. smart phone, tablet, note book, and so on.

According to an embodiment of the invention, the antenna device <NUM> may comprise at least one antenna. The antenna device <NUM> may be configured to receive an external received signal S1, and transmit the received signal S1 to the circulator <NUM>.

According to an embodiment of the invention, the circulator <NUM> may transmit the signal which comes in receiving direction (i.e. received signal S1) to the notch filter <NUM>, and then transmit the reflected signal (i.e. the signal cannot pass through the notch filter <NUM>) from the notch filter <NUM> to the transceiver <NUM>. In addition, the circulator <NUM> may transmit the signal which comes in transmit direction (i.e. the signal from the transceiver <NUM>) to the antenna device <NUM>.

According to an embodiment of the invention, after the notch filter <NUM> receives the received signal S1, the notch filter <NUM> may reflect the signal in the frequency band which is being used by the receiving device <NUM> (i.e. the in-band signal S1IN in the received signal S1) to the circulator <NUM>. That is to say, the notch filter <NUM> may merely let the signal outside the frequency band (e.g. the frequency band whose central frequency is <NUM>, but the invention should not be limited thereto) which is being used by the receiving device <NUM> (i.e. the out-band signal S1OUT in the received signal S1) pass through the notch filter <NUM>. The out-band signal S1OUT passing through the notch filter <NUM> may be transmitted to the processor <NUM>. The in-band signal S1IN not passing through the notch filter <NUM> may be reflected to the circulator <NUM> and then, the circulator <NUM> transmits the in-band signal S1IN to the adjustable attenuator <NUM>. Specifically, when there is a signal received in the receiving direction (e.g. in-band signal S1IN), the processor <NUM> may tell the switch circuit <NUM> to form the conducting path between the circulator <NUM> and the adjustable attenuator <NUM>, and when there is a signal received in the transmission direction (e.g. request packet S2), the processor <NUM> may order the switch circuit <NUM> to form the conducting path between the circulator <NUM> and the transceiver <NUM>. Therefore, after the switch circuit <NUM> receives the in-band signal S1IN, the processor <NUM> may order the switch circuit <NUM> to form the conducting path between the circulator <NUM> and the adjustable attenuator <NUM> to transmit the in-band signal S1IN to the adjustable attenuator <NUM>. The adjustable attenuator <NUM> may determine whether to adjust the attenuation value corresponding to the in-band signal S1IN according to the indication I1 form the processor <NUM> to output the in-band signal S1IN'. The adjustable attenuator <NUM> may transmit the in-band signal S1IN' to the transceiver <NUM>. The transceiver <NUM> may process the in-band signal S1IN' to generate the information I2 related to the in-band signal S1IN'. Then, the transceiver <NUM> may transmit the information I2 related to the in-band signal S1IN' to the processor <NUM>. The processor <NUM> may determine whether the attenuation value corresponding to the in-band signal S1IN' which has been adjusted by the adjustable attenuator <NUM> needs to be adjusted again to generate new in-band signal S1IN'. According to the embodiments of the invention, the information I2 related to the in-band signal S1IN' may comprise one or more of the signal-to noise ratio (SNR) of the in-band signal S1IN', the signal level, and the signal quality of the in-band signal S1IN', but the invention should be limited thereto.

According to an embodiment of the invention, after the processor <NUM> receives the out-band signal S1OUT, the processor <NUM> may obtain the information related to the out-band signal S1OUT (e.g. the signal level of the out-band signal S1OUT, but the invention should not be limited thereto) according to the out-band signal S1OUT. According to the information related to the out-band signal S1OUT, the processor <NUM> may determine whether there are other signals in the adjacent frequency bands and determine the influence of these signals on the frequency band which is being used by the receiving device <NUM>. If the processor <NUM> determines that no out-band signal S1OUT is received, it means that no signal is leaking into the frequency band which is being used by the receiving device <NUM>, or it means that the signal level of the out-band signal S1OUT is too low (e.g. the signal level of the out-band signal S1OUT is lower than a threshold) to affect the in-band signal S1IN (i.e. in this case, the processor <NUM> may also determine that no signal is leaking into the frequency band which is being used by the receiving device <NUM>).

According to an embodiment of the invention, the processor <NUM> may determine how to adjust the attenuation value corresponding to the in-band signal S1IN according to the information related to the out-band signal S1OUT and the in-band signal S1IN'. The details about how to adjust the attenuation value corresponding to the in-band signal S1IN will be illustrated in following embodiments.

According to an embodiment of the invention, before the processor <NUM> determines how to adjust the attenuation value corresponding to the in-band signal S1IN according to the information related to the out-band signal S1OUT and the in-band signal S1IN', the processor <NUM> may determine whether the packet error rate is lower than a threshold first. For example, if the threshold is <NUM>%, the processor <NUM> may determine whether the packet error rate is lower than <NUM>%. If the packet error rate is lower than the threshold (e.g. <NUM>%), the processor <NUM> may maintain the attenuation value corresponding to the in-band signal S1IN without adjusting the attenuation value corresponding to the in-band signal S1IN. If the packet error rate is not lower than the threshold (e.g. <NUM>%), the processor <NUM> may determine how to adjust the attenuation value corresponding to the in-band signal S1IN according to the information related to the out-band signal S1OUT and the in-band signal S1IN.

According to an embodiment of the invention, when the processor <NUM> determines how to adjust the attenuation value corresponding to the in-band signal S1IN according to the information related to the out-band signal S1OUT and the in-band signal S1IN, the processor <NUM> may determine the signal level of the out-band signal S1OUT is greater than a first threshold and whether the signal quality of the in-band signal S1IN' is greater than a second threshold. For example, the processor <NUM> may determine whether the signal level of the out-band signal S1OUT is greater than 10dBm and whether the SNR of the in-band signal S1IN' is greater than a certain second threshold (e.g. <NUM> dB), but the invention should not be limited thereto.

According to an embodiment of the invention, when the signal level of the out-band signal S1OUT is greater than the first threshold (e.g. the signal level of the out-band signal S1OUT is greater than 10dBm) and the signal quality of the in-band signal S1IN' is greater than the second threshold (e.g. the SNR of the in-band signal S1IN' is greater than a certain second threshold), the processor <NUM> may command the adjustable attenuator <NUM> to increase the attenuation value corresponding to the in-band signal S1IN (e.g. increase 1dB for the attenuation value corresponding to the in-band signal S1IN (e.g. the attenuation value is increased from 3dB to 4dB), but the invention should not be limited thereto). In the embodiment of the invention, when the processor <NUM> determines that the attenuation value corresponding to the in-band signal S1IN needs to be increased, the processor <NUM> may further determine whether the attenuation value corresponding to the in-band signal S1IN has adjusted to an upper limit (i.e. the attenuation value corresponding to the in-band signal S1IN cannot be increased anymore). If the attenuation value corresponding to the in-band signal S1IN has adjusted to the upper limit value, the processor <NUM> may activate a clear channel assessment (CCA) mechanism. If the attenuation value corresponding to the in-band signal S1IN has not adjusted to the upper limit value, the processor <NUM> may tell the adjustable attenuator <NUM> to increase the attenuation value corresponding to the in-band signal S1IN (e.g. increase 1dB for the attenuation value corresponding to the in-band signal S1IN, but the invention should not be limited thereto). In the embodiment, when the attenuation value corresponding to the in-band signal S1IN has been increased, the processor <NUM> may again determine whether the packet error rate is lower than the threshold to determine whether the attenuation value corresponding to the in-band signal S1IN needs to be adjusted again. It should be noted that the CCA mechanism is common communication technology, so the details will not be discussed in more detail herein.

According to an embodiment, when the signal level of the out-band signal S1OUT is greater than the first threshold (e.g. the signal level of the out-band signal S1OUT is greater than 10dBm) and the signal quality of the in-band signal S1IN' is not greater than the second threshold (e.g. the SNR of the in-band signal S1IN' is not greater than a certain second threshold), the processor <NUM> may tell the adjustable attenuator <NUM> to decrease the attenuation value corresponding to the in-band signal S1IN (e.g. decrease 1dB for the attenuation value corresponding to the in-band signal S1IN, but the invention should not be limited thereto). In the embodiment, when the attenuation value corresponding to the in-band signal S1IN has been increased, the processor <NUM> may again determine whether the packet error rate is lower than the threshold to determine whether the attenuation value corresponding to the in-band signal S1IN needs to be adjusted again. In the embodiment, when the processor <NUM> determines that the attenuation value corresponding to the in-band signal S1IN needs to be decreased, the processor <NUM> may further determine whether the attenuation value corresponding to the in-band signal S1IN has been adjusted to a lower limit (i.e. the attenuation value corresponding to the in-band signal S1IN cannot be decreased anymore). If the attenuation value corresponding to the in-band signal S1IN has been adjusted to the lower limit value, the processor <NUM> may tell the transceiver <NUM> to send a request packet S2 to the transmitting device (not shown in figures) which transmits the received signal S1 to the receiving device <NUM> to ask the transmitting device that transmits the received signal S1 to the receiving device <NUM> to increase its transmission power. For example, the processor <NUM> may tell the transceiver <NUM> to send a request packet S2 to the transmitting device which transmits the received signal S1 to the receiving device <NUM> to ask the transmitting device to increase its transmission power by <NUM> dB, but the invention should not be limited thereto. In addition, if the processor <NUM> of the receiving device <NUM> knows that the transmission power of the transmitting device has reached the maximum value, the processor <NUM> may activate CCA mechanism. If the attenuation value corresponding to the in-band signal S1IN has not been adjusted to the lower limit value, the processor <NUM> may command the adjustable attenuator <NUM> to decrease the attenuation value corresponding to the in-band signal S1IN (e.g. decrease 1dB for the attenuation value corresponding to the in-band signal S1IN, but the invention should not be limited thereto). In the embodiment, when the transmitting device has increased its transmission power, the processor <NUM> may again determine whether the packet error rate is lower than the threshold to determine whether to adjust the attenuation value corresponding to the in-band signal S1IN again.

According to an embodiment of the invention, when the signal level of the out-band signal S1OUT is not greater than the first threshold (e.g. the signal level of the out-band signal S1OUT is not greater than 10dBm) and the signal quality of the in-band signal S1IN is greater than the second threshold (e.g. the SNR of the in-band signal S1IN' is greater than a certain second threshold, i.e. in a high SNR state), the processor <NUM> may order the adjustable attenuator <NUM> to increase the attenuation value corresponding to the in-band signal S1IN (e.g. increase 1dB for the attenuation value corresponding to the in-band signal S1IN (e.g. the attenuation value is increased from 3dB to 4dB), but the invention should not be limited thereto). In addition, in the embodiment, because the signal level of the out-band signal S1OUT is not greater than the first threshold, the processor <NUM> cannot definitely determine whether the noise of the in-band signal S1IN is from other signals in the frequency band which is being used by the receiving device <NUM> or from the out-band signal leaking into the frequency band which is being used by the receiving device <NUM>. Therefore, in the embodiment of the invention, the processor <NUM> may further determines whether the noise floor is higher that a threshold (e.g. 5dB). If the noise floor is higher that the threshold (e.g. the noise floor is higher than 5dB), the processor <NUM> may further determine whether the attenuation value corresponding to the in-band signal S1IN has adjusted to an upper limit (i.e. the attenuation value corresponding to the in-band signal S1IN cannot be increased anymore). If the attenuation value corresponding to the in-band signal S1IN has adjusted to the upper limit value, the processor <NUM> may activate the CCA mechanism. If the attenuation value corresponding to the in-band signal S1IN has not adjusted to the upper limit value, the processor <NUM> may tell the adjustable attenuator <NUM> to increase the attenuation value corresponding to the in-band signal S1IN (e.g. increase 1dB for the attenuation value corresponding to the in-band signal S1IN (e.g. the attenuation value is increased from 3dB to 4dB), but the invention should not be limited thereto). If the noise floor is not higher that the threshold (e.g. the noise floor is not higher than 5dB), the processor <NUM> may activate the CCA mechanism directly. In the embodiment, when the attenuation value corresponding to the in-band signal S1IN has been increased, the processor <NUM> may again determine whether the packet error rate is lower than the threshold to determine whether the attenuation value corresponding to the in-band signal S1IN needs to be adjusted again. It should be noted that, because the in-band signal S1IN' is in the high SNR state in the embodiment, even the signal level of the noise is high (i.e. the noise floor is higher that the threshold), but the signal level of the noise is still much lower than the signal level in-band signal S1IN'. Therefore, in the embodiment, the attenuation value corresponding to the in-band signal S1IN can be adjusted to decrease the noise.

According to an embodiment of the invention, when the signal level of the out-band signal S1OUT is not greater than the first threshold (e.g. the signal level of the out-band signal S1OUT is not greater than 10dBm) and the signal quality of the in-band signal S1IN' is not greater than the second threshold (e.g. the SNR of the in-band signal S1IN' is not greater than a certain second threshold), the processor <NUM> may tell the adjustable attenuator <NUM> to decrease the attenuation value corresponding to the in-band signal S1IN (e.g. decrease 1dB for the attenuation value corresponding to the in-band signal S1IN, but the invention should not be limited thereto). In the embodiment, the processor <NUM> may determine whether the attenuation value corresponding to the in-band signal S1IN has been adjusted to a lower limit (i.e. the attenuation value corresponding to the in-band signal S1IN cannot be decreased anymore). If the attenuation value corresponding to the in-band signal S1IN has been adjusted to the lower limit value, the processor <NUM> may command the transceiver <NUM> to send a request packet S2 to the transmitting device (not shown in figures) which transmits the received signal S1 to the receiving device <NUM> to ask the transmitting device that transmits the received signal S1 to the receiving device <NUM> to increase its transmission power. For example, the processor <NUM> may tell the transceiver <NUM> to send the request packet S2 to the transmitting device which transmits the received signal S1 to the receiving device <NUM> to ask the transmitting device to increase its transmission power by <NUM> dB, but the invention should not be limited thereto. In addition, in the embodiment, because the signal level of the out-band signal S1OUT is not greater than the first threshold, the processor <NUM> cannot definitely determine whether the noise of the in-band signal S1IN is from other signals in the frequency band which is being used by the receiving device <NUM> or from the out-band signal leaking into the frequency band which is being used by the receiving device <NUM>. Therefore, in the embodiment of the invention, the processor <NUM> may further determine whether the noise floor is higher that a threshold (e.g. 5dB). If the noise floor is higher that the threshold (e.g. the noise floor is higher than 5dB), the processor <NUM> may activate the CCA mechanism. If the noise floor is not higher that the threshold (e.g. the noise floor is not higher than 5dB), the processor <NUM> may determine that the signal level of the in-band signal S1IN is too small, and therefore, the processor <NUM> may not adjust the attenuation value corresponding to the in-band signal S1IN. It should be noted that because in the embodiment, the in-band signal S1IN' is in the low SNR state (i.e. the signal level of the noise is almost equivalent to the signal level of the in-band signal S1IN'), and therefore, if the noise floor is not higher that the threshold (the signal level of the noise is small), it means that the low SNR of the in-band signal S1IN is occurred because the signal level of the in-band signal S1IN is too small, not because of the noise. If the attenuation value corresponding to the in-band signal S1IN has not been adjusted to the lower limit value, the processor <NUM> may order the adjustable attenuator <NUM> to decrease the attenuation value corresponding to the in-band signal S1IN (e.g. decrease 1dB for the attenuation value corresponding to the in-band signal S1IN, but the invention should not be limited thereto). In the embodiment, when the transmitting device increase its transmission power or the attenuation value corresponding to the in-band signal S1IN is decreased, the processor <NUM> may again determine whether the packet error rate is lower than the threshold to determine whether to adjust the attenuation value corresponding to the in-band signal S1IN again.

According to an embodiment of the invention, when the signal quality of the in-band signal S1IN' is not greater than the second threshold (e.g. the SNR of the in-band signal S1IN' is not greater than a certain second threshold), the processor <NUM> may directly command the transceiver <NUM> to send a request packet S2 to the transmitting device (not shown in figures) which transmits the received signal S1 to the receiving device <NUM>, to ask the transmitting device that transmits the received signal S1 to the receiving device <NUM> to increase its transmission power. For example, the processor <NUM> may order the transceiver <NUM> to send the request packet S2 to the transmitting device which transmits the received signal S1 to the receiving device <NUM> to ask the transmitting device to increase its transmission power by <NUM> dB, but the invention should not be limited thereto. That is to say, in the embodiment, when the signal quality of the in-band signal S1IN' is too bad, the processor <NUM> may directly order the transceiver <NUM> to send the request packet S2 to the transmitting device. In addition, in the embodiment, if the processor <NUM> of the receiving device <NUM> knows that the transmission power of the transmitting device has reached the maximum value, the processor <NUM> may activate a CCA mechanism.

<FIG> is a block diagram of a receiving device <NUM> according to another embodiment of the invention. As shown in <FIG>, the receiving device <NUM> comprises an antenna device <NUM>, a circulator <NUM>, a band-pass filter <NUM>, a transceiver <NUM>, a processor <NUM>, an adjustable attenuator <NUM> and a first switch circuit <NUM>. It should be noted that the block diagram shown in <FIG> is only used to illustrate the embodiments of the invention, but the invention should not be limited thereto. The receiving device <NUM> may comprise other elements. For example, the receiving device <NUM> may comprise a radio frequency (RF) signal processing circuit and a base band (BS) signal processing circuit.

The difference between <FIG> and <FIG> is that the band-pass filter <NUM> is adopted to separate the received signal S1 in the receiving device <NUM> of <FIG>.

As shown in <FIG>, according to an embodiment of the invention, when the band-pass filter <NUM> receives the received signal S1, the band-pass filter <NUM> may reflect the signal which is not in the frequency band which is being used by the receiving device <NUM> (i.e. the out-band signal S1OUT in the received signal S1) to the circulator <NUM>. That is to say, the band-pass filter <NUM> may merely let the signal in the frequency band (e.g. the frequency band whose central frequency is <NUM>, but the invention should not be limited thereto) which is being used by the receiving device <NUM> (i.e. the in-band signal S1IN in the received signal S1) pass through the band-pass filter <NUM>.

The in-band signal S1IN passing through the band-pass filter <NUM> may transmit to the adjustable attenuator <NUM>. The adjustable attenuator <NUM> may determine whether to adjust the attenuation value corresponding to the in-band signal S1IN according to the indication I1 form the processor <NUM> to output the in-band signal S1IN'. The adjustable attenuator <NUM> may transmit the in-band signal S1IN' to the transceiver <NUM>. The transceiver <NUM> may process the in-band signal S1IN' to generate the information I2 related to the in-band signal S1IN'. Then, the transceiver <NUM> may transmit the information I2 related to the in-band signal S1IN' to the processor <NUM>.

The out-band signal S1OUT not passing through the band-pass filter <NUM> may be reflected to the circulator <NUM>. Then, the circulator <NUM> may transmit the out-band signal S1OUT to the processor <NUM>. Specifically, when there is a signal received in the receiving direction (e.g. out-band signal S1OUT), the processor <NUM> may tell the first switch circuit <NUM> to form the conducting path between the circulator <NUM> and the processor <NUM>, and when there is a signal received in the transmission direction (e.g. request packet S2), the processor <NUM> may tell the first switch circuit <NUM> to form the conducting path between the circulator <NUM> and the transceiver <NUM>. Therefore, after the first switch circuit <NUM> receives the out-band signal S1OUT, the processor <NUM> may order the first switch circuit <NUM> to form the conducting path between the circulator <NUM> and the processor <NUM> to transmit the out-band signal S1OUT to the processor <NUM>.

Other operations of the receiving device <NUM> of <FIG> are similar to the receiving device <NUM> of <FIG>, therefore, details will not be repeated again.

In <FIG> and <FIG>, the notch filter <NUM> and the band-pass filter <NUM> are respectively adopted in the receiving device <NUM>, but the invention should not be limited thereto. Any equivalent circuit of the notch filter <NUM> and the band-pass filter <NUM> also can be adopted. Furthermore, other circuits which may be configured to separate the received signal S1 also can be adopted.

<FIG> is a flow chart illustrating a method for dynamically adjusting the attenuation value of the received signal according to an embodiment of the invention. The method for dynamically adjusting the attenuation value of the received signal can be applied to the receiving device <NUM>. As shown in <FIG>, in step S210, a circulator of the receiving device <NUM> transmits a received signal to a filter circuit (the notch filter <NUM> or the band-pass filter <NUM>) of the receiving device <NUM>. In step S220, the filter circuit of the receiving device <NUM> separates the out-band signal and the in-band signal from the received signal. In step S230, a processor of the receiving device <NUM> determines how to adjust the attenuation value corresponding to the in-band signal according to the information related to the out-band signal and the information related to the in-band signal which has been processed by an adjustable attenuator and a transceiver of the receiving device <NUM>.

In some embodiments of the invention, in the method for dynamically adjusting the attenuation value of the received signal, an adjustable attenuator of the receiving device <NUM> is configured to adjust the attenuation value corresponding to the in-band signal.

In some embodiments of the invention, in step S230, the processor of the receiving device <NUM> may determine the signal level of the out-band signal is greater than a first threshold and determine the signal quality of the in-band signal is greater than a second threshold to determine how to adjust the attenuation value corresponding to the in-band signal.

In some embodiments of the invention, before step S230, the processor of the receiving device <NUM> may determine whether the packet error rate of the received signal is lower than a threshold. If the packet error rate of the received signal is lower than the threshold, the processor of the receiving device <NUM> may maintain the attenuation value corresponding to the in-band signal without adjusting the attenuation value corresponding to the in-band signal. If the packet error rate of the received signal is not lower than the threshold, the processor of the receiving device <NUM> may determine how to adjust the attenuation value corresponding to the in-band signal according to the information of out-band signal and in-band signal. Details will be illustrated through <FIG> and <FIG>, but the invention should not be limited thereto.

<FIG> is a flow chart illustrating step S320 according to an embodiment of the invention. The method shown in <FIG> can be applied to the receiving device <NUM>. As shown in <FIG>, in step S310, the processor of the receiving device <NUM> may determine whether the packet error rate of the received signal is lower than a threshold. If the packet error rate of the received signal is lower than the threshold, step S320 is performed.

In step S320, the processor of the receiving device <NUM> may maintain the attenuation value corresponding to the in-band signal without adjusting the attenuation value corresponding to the in-band signal. If the packet error rate of the received signal is not lower than the threshold, step S330 is performed.

In step S330, the processor of the receiving device <NUM> may determine whether the signal level of the out-band signal is greater than a first threshold and determine whether the signal quality of the in-band signal is greater than a second threshold.

In step S340, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor of the receiving device <NUM> may tell the adjustable attenuator to increase the attenuation value corresponding to the in-band signal. In an embodiment of the invention, in step S340, if the attenuation value corresponding to the in-band signal has been adjusted to the upper limit value, the processor of the receiving device <NUM> may activate a clear channel assessment (CCA) mechanism.

In step S350, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor of the receiving device <NUM> may order the adjustable attenuator to decrease the attenuation value corresponding to the in-band signal. In an embodiment of the invention, in step S350, if the attenuation value corresponding to the in-band signal has been adjusted to the lower limit value, the processor of the receiving device <NUM> may tell the transceiver of the receiving device <NUM> to transmit a request packet to the transmitting device that transmits the received signal to the receiving device to ask the transmitting device to adjust its transmission power.

In step S360, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor of the receiving device <NUM> may command the adjustable attenuator to increase the attenuation value corresponding to the in-band signal.

In step S370, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor of the receiving device <NUM> may tell the adjustable attenuator to decrease the attenuation value corresponding to the in-band signal. In an embodiment of the invention, in step S370, if the attenuation value corresponding to the in-band signal has been adjusted to the lower limit value, the processor of the receiving device <NUM> may order the transceiver of the receiving device <NUM> to transmit a request packet to the transmitting device which transmits the received signal to the receiving device to ask the transmitting device to adjust its transmission power.

In the embodiment of <FIG>, when the attenuation value corresponding to the in-band signal has been increased or decreased, the flow will back to step S310.

<FIG> is a flow chart illustrating step S320 according to another embodiment of the invention. The method shown in <FIG> can be applied to the receiving device <NUM>. As shown in <FIG>, in step S410, the processor of the receiving device <NUM> may determine whether the packet error rate of the received signal is lower than a threshold. If the packet error rate of the received signal is lower than the threshold, step S420 is performed.

In step S420, the processor of the receiving device <NUM> may maintain the attenuation value corresponding to the in-band signal without adjusting the attenuation value corresponding to the in-band signal. If the packet error rate of the received signal is not lower than the threshold, step S430 is performed.

In step S430, the processor of the receiving device <NUM> may determine whether the signal level of the out-band signal is greater than a first threshold and determine whether the signal quality of the in-band signal is greater than a second threshold.

In step S440, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor of the receiving device <NUM> may order the adjustable attenuator to increase the attenuation value corresponding to the in-band signal.

In step S450, when the signal level of the out-band signal is greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor of the receiving device <NUM> may order the transceiver of the receiving device <NUM> to transmit a request packet to a transmitting device which transmits the received signal to the receiving device to ask the transmitting device to adjust its transmission power.

In step S460, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is greater than the second threshold, the processor of the receiving device <NUM> may order the adjustable attenuator to increase the attenuation value corresponding to the in-band signal.

In step S470, when the signal level of the out-band signal is not greater than the first threshold and the signal quality of the in-band signal is not greater than the second threshold, the processor of the receiving device <NUM> may order the transceiver of the receiving device <NUM> to transmit a request packet to a transmitting device which transmits the received signal to the receiving device to ask the transmitting device to adjust its transmission power.

In the embodiment of <FIG>, when the attenuation value corresponding to the in-band signal has been increased or decreased, the flow will back to step S410.

According to the method for dynamically adjusting the attenuation value of the received signal provided in the embodiments of the invention, the receiving device may determine the effect of the out-band signal for the in-band signal and dynamically adjust the attenuation value corresponding to the in-band signal according to the determination result. Therefore, in the method for dynamically adjusting the attenuation value of the received signal provided in the embodiments of the invention, the receiving device may more accurately determine the source of the noise and adjust the attenuation value corresponding to the in-band signal to maintain the stability of the communication quality.

Use of ordinal terms such as "first", "second", "third", etc., in the disclosure and claims is for description. It does not by itself connote any order or relationship.

The steps of the method described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module (e.g., including executable instructions and related data) and other data may reside in a data memory such as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of computer-readable storage medium known in the art. A sample storage medium may be coupled to a machine such as, for example, a computer/processor (which may be referred to herein, for convenience, as a "processor") such that the processor can read information (e.g., code) from and write information to the storage medium. A sample storage medium may be integral to the processor. The ASIC may reside in user equipment. Alternatively, the processor and the storage medium may reside as discrete components in user equipment. Moreover, in some aspects any suitable computer-program product may comprise a computer-readable medium comprising codes relating to one or more of the aspects of the disclosure. In some aspects a computer program product may comprise packaging materials.

The above paragraphs describe many aspects of the invention. Obviously, the teaching of the invention can be accomplished by many methods, and any specific configurations or functions in the disclosed embodiments only present a representative condition. Those who are skilled in this technology will understand that all of the disclosed aspects of the invention can be applied independently or be incorporated.

Claim 1:
A receiving device (<NUM>), comprising:
an antenna device (<NUM>), configured to receive a received signal;
a filter circuit (<NUM>, <NUM>), configured to separate an in-band signal and an out-band signal from the received signal, wherein the in-band signal passes through the filter and the out-band signal is reflected by the filter, or wherein the out-band signal passes through the filter and the in-band signal is reflected by the filter; a transceiver (<NUM>);
an adjustable attenuator (<NUM>) configured to adjust an attenuation value to attenuate the in-band signal and transmit the adjusted in-band signal to the transceiver (<NUM>);
a circulator (<NUM>), coupled to the antenna device (<NUM>) and the filter circuit (<NUM>, <NUM>), wherein the circulator (<NUM>) receives the received signal from the antenna device (<NUM>) via a first port and transmits the received signal to the filter circuit (<NUM>, <NUM>) via a second port, and wherein the circulator (<NUM>) receives the reflected signal from the filter circuit (<NUM>, <NUM>) via the second port and transmits the reflected signal via a third port; and
a processor (<NUM>), coupled to the adjustable attenuator (<NUM>) and the transceiver (<NUM>), and according to information related to the out-band signal and information related to the in-band signal which has been processed by the adjustable attenuator (<NUM>) and the transceiver (<NUM>), determining how to adjust the attenuation value corresponding to the in-band signal.