摘要:
Signal instances are detected from within a long period of a received radiofrequency RF signal envelope, grouped according to signal level, and periodicities are determined among the grouped signal instances. Periodicity of one of the groups is matched to a known periodicity, and a frequency domain is estimated at a time instance derived from the matched periodicity. If an expected frequency pattern is found that occupies the derived time instance in the estimated frequency domain, then a receiver is synchronized to a candidate signal that lies within the frequency pattern. Then content of the candidate signal is decoded and that content is used to access a cognitive radio system (e.g., register to the system, start the normal operation in the network such as spectrum detection and/or transmission in a traffic channel, etc.).
摘要:
A method for operating a receiver and a device are provided. The device comprises a first and a second antenna, a receiver operationally coupled to the first antenna and a transceiver operationally coupled to the second antenna. The receiver receives information in bursts on a first band of radio frequencies. A controller of the device measures signal strength of the information received with the receiver, compares the measured signal strength to a reference value and enables operation of the transceiver if the measured signal strength is above the reference value, and limits operation of the transceiver during reception of the bursts if the measured signal strength is below the reference value.
摘要:
A method for operating a receiver and a device are provided. The device comprises a first and a second antenna, a receiver operationally coupled to the first antenna and a transceiver operationally coupled to the second antenna. The receiver receives information in bursts on a first band of radio frequencies. A controller of the device measures signal strength of the information received with the receiver, compares the measured signal strength to a reference value and enables operation of the transceiver if the measured signal strength is above the reference value, and limits operation of the transceiver during reception of the bursts if the measured signal strength is below the reference value.
摘要:
A base station and a method of configuring a base station are provided in a cellular telecommunication system, wherein the base station comprises an electrically tunable duplex filter with a tuning range covering at least two parallel sub-bands used in the telecommunication system. The electrically tunable duplex filter is tunable on site to a sub-band allocated to the base station, thus enabling an increased flexibility in selecting a fixed frequency band to be used in the lower frequency stages in the transceiver and the base band parts of the base station.
摘要:
A method, terminal, and computer program are disclosed to reduce radio interference in a wireless communications device having a combination of a wireless telephone unit, such as a GSM cellular phone, and a short range wireless communications unit, such as a WLAN communications unit or a Bluetooth communications unit. An interference avoidance subsystem in the wireless communications device is connected between the GSM frequency hopping logic and the Bluetooth frequency hopping logic. Bluetooth frequency hopping information and time domain operation information are input from the Bluetooth frequency hopping logic to the interference avoidance subsystem. GSM frequency hopping information and time domain operation information are input from the GSM frequency hopping logic to the interference avoidance subsystem. The interference avoidance subsystem then uses this input data to calculate the interference probability between co-existing Bluetooth received signals and GSM transmitted signals. The interference avoidance subsystem then compares the calculated interference probability with the required Bluetooth packet error rate limit for the current application. If the interference probability exceeds the required Bluetooth packet error rate limit, the interference avoidance subsystem sends a signal to the Bluetooth frequency hopping logic to change the Bluetooth frequencies.
摘要:
A base station in a radio system includes a transmitter that forms a signal to be transmitted by a transmission antenna of the base station, a mechanism forming a portion of the signal to be transmitted in a transmission frequency, a mechanism shifting the formed signal portion into a receiving frequency, where the separation between the receiving frequency and the transmission frequency differs from a frequency duplex used in the radio system, and a mechanism receiving the frequency-shifted signal portion.
摘要:
The invention relates to a receiver in a radio system that contains receiving means for receiving a signal, amplification means for amplifying the received signal with an amplification step, and means for limiting the frequency band of the amplified signal. The receiver also contains correction means for correcting the step response of the limiting means by using step response information defined in advance. The invention also relates to a method for correcting the step response.
摘要:
Signal instances are detected from within a long period of a received radiofrequency RF signal envelope, grouped according to signal level, and periodicities are determined among the grouped signal instances. Periodicity of one of the groups is matched to a known periodicity, and a frequency domain is estimated at a time instance derived from the matched periodicity. If an expected frequency pattern is found that occupies the derived time instance in the estimated frequency domain, then a receiver is synchronized to a candidate signal that lies within the frequency pattern. Then content of the candidate signal is decoded and that content is used to access a cognitive radio system (e.g., register to the system, start the normal operation in the network such as spectrum detection and/or transmission in a traffic channel, etc.).
摘要:
Method, apparatus, and computer program product embodiments are disclosed for wireless resource sharing between heterogeneous wireless networks to enable coexistence of secondary networks. An example embodiment of the invention includes a method, comprising: receiving, at an apparatus or entity, information associated with a wireless network; determining, by the apparatus or entity, a geographic communication area and one or more geographic interference areas associated with the wireless network based on the received information; transmitting, by the apparatus or entity, a message to a destination to register the wireless network and the determined geographic communication area and one or more geographic interference areas associated with the wireless network; and receiving, by the apparatus or entity, confirmation of the registering of the wireless network at the destination and information associated with zero or more wireless networks that at least one of potentially interfere with the determined geographic communication area associated with the wireless network, or potentially experience interference caused by the determined one or more interference areas associated with the wireless network.
摘要:
At least some exemplary embodiments of the invention enable a node to transmit synchronization information to other near-by nodes in a cognitive radio network during a transmission period. In one exemplary embodiment, an internal clock is compared to received synchronization information, a length of a next transmission period is set as a function of the comparing, and synchronization information is transmitted only once during the next transmission period.