摘要:
A linearized three state phase detector (300) that exhibits a linear transfer function of phase to current or charge at and around the zero phase error region. The inputs to the D flip-flops (301 and 302) are tied to a logic high. the first flip-flop (301) is clocked with reference signal F.sub.r while the other flip-flop (302) is clocked with a variable frequency feedback signal F.sub.v. F.sub.v is typically from a voltage controlled oscillator in a phase locked loop. The outputs of the flip-flops are ANDed together with the result of this operation going through a delay element (304) before reseting one of the flip-flops (301). The other flip-flop (302) is reset by the output of the AND gate (304) without the delay element (304). Each flip-flop output enables a charge pump--one negative polarity (306) and one positive polarity (305). The present invention will maintain a lock condition in a phase locked loop by extending the DOWN pulse enabling the negative polarity charge pump (306) to the same width as the UP pulse that enables the positive pump (305). This will create a net zero charge from the present invention.
摘要:
A method and apparatus for allocating spectrum within a wireless communication system is provided herein. During operation, a first base station will determine a location of a UE wishing to transmit. A database will be accessed containing wireless coverage area information for base stations with overlapping coverage with the first base station. Based on this information the first base station will determine if the UE is within an overlapping coverage area of multiple base stations. Spectrum will be assigned to the wireless equipment in a guard band, based at least in part on the determination that the UE is not within the overlapping coverage area.
摘要:
In certain embodiments of a cognitive radio, a method of establishing operational policies, involves determining that a new policy decision should be made; requesting a policy decision from an authority having more computing power than the cognitive radio; receiving the policy decision from the authority; and implementing the policy decision in the cognitive radio. Other embodiments may incorporate more, fewer or other elements.
摘要:
During operation of a secondary communication system, nodes having different channel monitoring capabilities or requirements will cooperatively monitor possible frequencies for transmissions, each node using only a subset of all possible modulation sensing schemes. All nodes will share channel occupancy information to other nodes within the communication system. For example, a first group of nodes may monitor possible frequencies for television transmissions, while a second group of nodes may monitor the possible frequencies for APCO 25 transmissions. A group of nodes may also cooperatively monitor possible frequencies for more than one type of modulation transmission. Channel information will be shared among the nodes.
摘要:
A method (200) and device (100) provide an efficient linear power amplifier that generates a variable-envelope radio frequency RF signal. The method includes the steps of: A) using an efficient envelope-following unit to output a supply voltage in accordance with a variable envelope of an input baseband signal, wherein using the efficient envelope-following unit includes: 1) using a bandwidth-limiting mapping unit to determine a reference signal based on the baseband signal; and 2) using an envelope-tracking power converter to output a supply voltage, responsive to the reference signal, to the linear RF power amplifier; B) providing an RF input signal with amplitude and phase information to a linear RF power amplifier; and C) using the linear RF power amplifier to output a power-efficient amplified variable-envelope RF signal with substantially a same amplitude and phase information as the RF input signal.
摘要:
A frequency synthesizer (200) with temperature compensation and frequently multiplication. The synthesizer (200) having a temperature uncompensated frequency oscillator (202) coupled to a phase locked loop (206) including at least one temperature compensating and frequency multiplication element (208). The element (208) preferably being a multi-modulus divider. The element (208) is programmed by a control circuit (210) to vary as a function of temperature and to vary as a function of a fractional frequency multiplication factor. The element (208) also may provide adjustment of the nominal frequency of the frequency oscillator (202). The frequency oscillator (202) and preferably all the elements of the synthesizer (200) are temperature compensated by the element (208) to produce a temperature stable multiplied output frequency (238).
摘要:
A phase lock loop (PLL) frequency synthesizer is used in a radiotelephone to provide a reference frequency to a transmitter or a receiver. This particular PLL frequency synthesizer has a wide bandwidth control loop having a high current charge pump (417) and a narrow bandwidth control loop having a low current charge pump (411). A deadzone circuit (413) is used at an output of a phase detector (405) to control the application of an error signal to the high current charge pump (417). Additionally, the PLL frequency synthesizer utilizes a loop filter (419). The loop filter (419) receives two correction signals (409', 415') and provides a single control signal for the VCO (voltage controlled oscillator) (423). The loop filter contains two time constants formed from resistive and capacitive elements. The two time constants control the bandwidth of the two control loops.
摘要:
A cellular cordless telephone (10) operates with both a cordless base station (180) and a cellular base station (190) and cellular control terminal (196). In one embodiment (FIG. 2), a cellular cordless telephone (100) includes a cellular transceiver (120), antenna (128), keyboard (140), a display (180), handset (160), and microcomputer (130) together with a cordless transceiver (110) and antenna (118), all of which may be in a single housing. In another embodiment (FIG. 3), a cellular cordless telephone (200) includes a cellular telephone (220) and a cordless telephone transceiver (210) which may be a plugable module. Whenever cellular cordless telephone (10) is within range of cordless base station (180), telephone calls may be made over the cordless radio channel or transferred from the cellular radio channels to the cordless radio channel. If the cellular cordless telephone (10) thereafter moves out of range of the cordless base station (180), telephone calls may be made over the cellular radio channels or transferred from the cordless radio channel to one of the cellular telephone channels.
摘要:
Each user can contribute to an original search and to refining the results of the search. Preferences of all of the users are considered in the search even while those preferences can be kept private. In some embodiments of the present invention, at least two users each submit a search query. The multiple search queries are logically combined to produce one set of search results. The results can be reviewed by the users and refined if necessary. In some embodiments, a search query can be specified by a single user, but the search engine takes into consideration the stored preferences of multiple users (in addition to the search query itself, of course).
摘要:
During operation of a secondary communication system, nodes having different channel monitoring capabilities or requirements will cooperatively monitor possible frequencies for transmissions, each node using only a subset of all possible modulation sensing schemes. All nodes will share channel occupancy information to other nodes within the communication system. For example, a first group of nodes may monitor possible frequencies for television transmissions, while a second group of nodes may monitor the possible frequencies for APCO 25 transmissions. A group of nodes may also cooperatively monitor possible frequencies for more than one type of modulation transmission. Channel information will be shared among the nodes.