Abstract: A method of reducing interference between two communication systems operating in adjacent frequency bands and coexisting in a communication device is provided, and the two communication systems are a first communication system and a second communication system. The method includes deciding whether to perform an arbitration procedure on a downlink subframe of the first communication system according to a CINR of the first communication system and a RSSI of the second communication system; deciding whether to perform the arbitration procedure on an uplink subframe of the first communication system according to a transmit power of the first communication system and a RSSI value of the second communication system; and when deciding to perform the arbitration procedure on the downlink or uplink subframe, further deciding whether to send a specific packet to request one or more stations not to send packets to the second communication system.

Abstract: A method of reducing interference between two communication systems operating in adjacent frequency bands and coexisting in a communication device is provided, and the two communication systems are a first communication system using TDD and a second communication system which is content-based. The method includes deciding whether to perform an arbitration procedure on a downlink subframe of the first communication system according to a CINR of the first communication system and a RSSI of the second communication system; deciding whether to perform the arbitration procedure on an uplink subframe of the first communication system according to a transmit power of the first communication system and a RSSI value of the second communication system; and when deciding to perform the arbitration procedure on the downlink or uplink subframe, further deciding whether to send a specific packet to request one or more stations not to send packets to the second communication system.

Abstract: A receiver for receiving a target signal complying with a specific communication specification comprising a specific spectrum characteristic includes a detecting module for detecting a packet of an input signal, a transforming unit for transforming the packet from a time domain to a frequency domain to derive a spectrum characteristic of the input signal, and a determining unit for determining whether the input signal is the target signal according to the spectrum characteristic of the input signal. Therefore, the proposed receiver is able to reduce packet miss rate and false alarm rate while robust to a severe channel condition, and achieve fast and accurate signal quality detection.

Abstract: The present invention provides apparatus and methods for carrier frequency offset and phase compensation, which can compensate the phase rotation of an OFDM symbol resulted from carrier frequency offset between the receiver and transmitter of an OFDM System. The apparatus and method for carrier frequency offset compensation generates an estimated carrier frequency offset according to a phase error between estimated frequency responses of two consecutive received OFDM symbols within the pilot subchannel, and calculates an accumulated phase rotation, according to the estimated carrier frequency offset, for compensating the received OFDM symbol.

Abstract: The present invention provides an apparatus and an associated method for sampling timing compensation, which can estimate sampling frequency offset between the receiver and transmitter of a multi-carrier system according to estimated frequency responses of two consecutive received symbols within each pilot subchannel, and compensate an accumulated sampling timing offset resulted from the sampling frequency offset. When the accumulated timing offset is not large, the apparatus uses a phase rotator to compensate with a corresponding accumulated phase rotation in frequency domain. When the accumulated timing offset is large, the apparatus first compensates with a specific timing offset in time domain, and then uses the phase rotator to compensate with a phase rotation corresponding to the remaining timing offset in frequency domain. A timing controller is used to compensate with the specific timing offset by adjusting a clock generator or a cyclic prefix remover of the receiver.

Abstract: A rate adaptation method for a wireless communication apparatus includes: determining whether to use a first mode or a second mode according to at least one estimation value, where the first mode and the second mode correspond to different values of an overall data rate of the wireless communication apparatus. A wireless communication apparatus for performing wireless communication with rate adaptation includes: a processing circuit; and a wireless receiver and a wireless transmitter, both coupled to the processing circuit. The processing circuit determines at least one estimation value regarding communication quality of the wireless communication apparatus, and further determines whether to use a first mode or a second mode according to the estimation value, where the first mode and the second mode correspond to different values of an overall data rate of the wireless communication apparatus.

Abstract: A wireless communication system adapted for the IEEE 802.11 or IEEE 802.16 standard comprises a radio frequency (RF) receiver, an analog-to-digital converter (ADC), and an OFDM communication apparatus. The RF receiver receives a radio signal. The ADC converts the radio signal to a digital signal. The OFDM communication apparatus comprises a digital filter, a notch filter, a fast Fourier transform (FFT) processor, and a detection element. The digital filter processes the digital signal to generate a processed digital signal. The notch filter filters out interference of the processed signal to generate a notched signal according to a filter band. The FFT processor performs an FFT process on the notched signal to generate an FFT signal according to the processed digital signal. The detection element generates the filter band of the notch filter according to the FFT signal.

Abstract: An apparatus and method for estimating an I/Q imbalance parameter of a receiver and a transmitter. An apparatus for estimating an I/Q imbalance parameter of a receiver, the apparatus comprising: a signal generator; a transmitter; a receiver; and an estimator. An apparatus for estimating an I/Q imbalance parameter of a transmitter, the apparatus comprising: a signal generator; a transmitter; and an estimator.

Abstract: A receiver for receiving a target signal complying with a specific communication specification comprising a specific spectrum characteristic includes a detecting module for detecting a packet of an input signal, a transforming unit for transforming the packet from a time domain to a frequency domain to derive a spectrum characteristic of the input signal, and a determining unit for determining whether the input signal is the target signal according to the spectrum characteristic of the input signal. Therefore, the proposed receiver is able to reduce packet miss rate and false alarm rate while robust to a severe channel condition, and achieve fast and accurate signal quality detection.

Abstract: A WLAN system is disclosed. The system includes: an Analog Front-End (AFE) circuit, for converting between analog baseband data and digital baseband data; a Radio Frequency (RF) circuit, coupled to the AFE circuit, for converting between analog RF data and analog baseband data; and a baseband circuit, coupled to the AFE circuit, for processing the digital baseband data and dynamically setting at least a parameter of the WLAN system based on the content of the data, in order to control the power consumption level of the WLAN system.

Abstract: A symbol boundary detection device and a method thereof for use in a receiver of a multi-channel communication system. The device utilizes a threshold to make an auxiliary judgement so as to select a proper symbol boundary reference point within an early range. The threshold may be flexibly set in response to different characteristics of the systems. In addition, a pilot symbol guard interval matched filter is further utilized to determine whether a pilot symbol guard interval is received.

Abstract: The invention provides an automatic gain control and antenna selection method used in a receiver of a radio communication system. The received signal power is estimated by digital signal processing after analog-to-digital conversion in the system, in order to adjust the gain of the front end analog signal until the magnitude of the analog signal is adjusted to an optimum range of the digital signal processing. In addition, the ADC is utilized to estimate the signal power as the basis of the antenna selection.

Abstract: The present invention is an assigning system and method for assigning a plurality of rake finger tracking units of a rake receiver in a Code Division Multiple Access (CDMA) communication system. The plurality of rake finger tracking units is used for tracking a plurality of path signal of each multipath signal by a plurality of corresponding predetermined tracking time positions. The assigning system and method estimate a plurality of corresponding tracking ranges of the plurality of path signals and compare the plurality of predetermined tracking time positions with the plurality of tracking ranges. If there is more than one predetermined tracking time positions in one tracking range, the assigning system assigns a rake finger tracking unit corresponding to one of the tracking time positions to track the path signal corresponding to the tracking range.

Abstract: A symbol boundary detection device and a method thereof for use in a receiver of a multi-channel communication system. The device utilizes a threshold to make an auxiliary judgement so as to select a proper symbol boundary reference point within an early range. The threshold may be flexibly set in response to different characteristics of the systems. In addition, a pilot symbol guard interval matched filter is further utilized to determine whether a pilot symbol guard interval is received.

Abstract: The invention provides an automatic gain control and antenna selection method used in a receiver of a radio communication system. The received signal power is estimated by digital signal processing after analog-to-digital conversion in the system, in order to adjust the gain of the front end analog signal until the magnitude of the analog signal is adjusted to an optimum range of the digital signal processing. In addition, the ADC is utilized to estimate the signal power as the basis of the antenna selection.

Abstract: The present invention provides an apparatus and an associated method for sampling timing compensation, which can estimate sampling frequency offset between the receiver and transmitter of a multi-carrier system according to estimated frequency responses of two consecutive received symbols within each pilot subchannel, and compensate an accumulated sampling timing offset resulted from the sampling frequency offset. When the accumulated timing offset is not large, the apparatus uses a phase rotator to compensate with a corresponding accumulated phase rotation in frequency domain. When the accumulated timing offset is large, the apparatus first compensates with a specific timing offset in time domain, and then uses the phase rotator to compensate with a phase rotation corresponding to the remaining timing offset in frequency domain. A timing controller is used to compensate with the specific timing offset by adjusting a clock generator or a cyclic prefix remover of the receiver.

Abstract: The present invention provides apparatus and methods for carrier frequency offset and phase compensation, which can compensate the phase rotation of an OFDM symbol resulted from carrier frequency offset between the receiver and transmitter of an OFDM System. The apparatus and method for carrier frequency offset compensation generates an estimated carrier frequency offset according to a phase error between estimated frequency responses of two consecutive received OFDM symbols within the pilot subchannel, and calculates an accumulated phase rotation, according to the estimated carrier frequency offset, for compensating the received OFDM symbol.

Abstract: An apparatus and method for estimating an I/Q imbalance parameter of a receiver and a transmitter. An apparatus for estimating an I/Q imbalance parameter of a receiver, the apparatus comprising: a signal generator; a transmitter; a receiver; and an estimator. An apparatus for estimating an I/Q imbalance parameter of a transmitter, the apparatus comprising: a signal generator; a transmitter; and an estimator.

Abstract: The present invention is an assigning system and method for assigning a plurality of rake finger tracking units of a rake receiver in a Code Division Multiple Access (CDMA) communication system. The plurality of rake finger tracking units is used for tracking a plurality of path signal of each multipath signal by a plurality of corresponding predetermined tracking time positions. The assigning system and method estimate a plurality of corresponding tracking ranges of the plurality of path signals and compare the plurality of predetermined tracking time positions with the plurality of tracking ranges. If there is more than one predetermined tracking time positions in one tracking range, the assigning system assigns a rake finger tracking unit corresponding to one of the tracking time positions to track the path signal corresponding to the tracking range.