103 results about "Path gain" patented technology

Several open-loop calibration techniques for phase-locked-loop circuits (PLL) that provide a process, temperature and divider modulus independence for the loop bandwidth and damping factor are disclosed. Two categories of open-loop techniques are presented. The first method uses only a single measurement of the output frequency from the oscillator and adjusts a single PLL loop element that performs a simultaneous calibration of both the loop bandwidth and damping factor. The output frequency is measured for a given value of the oscillator control signal and the charge-pump current is adjusted such that it cancels the process variation of the oscillator gain. The second method uses two separate and orthogonal calibration steps, both of them based on the measurement of the output frequency from the oscillator when a known excitation is applied to the open loop signal path. In the first step the loop bandwidth is calibrated by adjusting the charge-pump current based on the measurement of the forward path gain when applying a constant phase shift between the two clocks that go to the phase frequency detector, while the integral path is hold to a constant value. During the second step the damping factor is calibrated by adjusting the value of the integral loop filter capacitor based on the measurement of the oscillator output frequency when excited with a voltage proportional with the integral capacitor value, while the proportional control component is zeroed-out.

A cellular system includes a first cell associated with a first base station, a second cell associated with a second base station, and a mobile radio currently served by the first base station. Distributed resource control may be used in which the first base station alone or in combination with the mobile station makes resource management decisions without having to involve a central controller. In ad-hoc networking, access points can manage resources in a distributed fashion. Relative path gain is determined for an uplink signal from the mobile radio. Relative path gain is based on a comparison of a first path gain related quantity for a mobile uplink signal to the second base station with a second path gain related quantity for the mobile uplink signal to the second base station. Uplink resources in the first cell are managed based on the relative path gain related quantity.

Transmission power relative to a propagation path having a variation in gain is controlled to increase communication channel capacity, and a data rate is controlled in accordance with the variation of the increased communication channel capacity. In order to increase the communication channel capacity, the transmission power is determined so that the sum of noise power (=received noise power / propagation path gain) converted into one at a transmitter and the transmission power becomes constant. As a result, contrary to the background art, the transmission power is controlled to be reduced when the propagation path gain decreases and to be increased when the propagation path gain increases.

A noise canceling system comprises a microphone generating a captured signal and a sound transducer radiating a sound canceling audio signal in the audio environment. A feedback path from the microphone to the sound transducer includes a non-adaptive canceling filter and a variable gain and receives the captured signal and generates a drive signal for the sound transducer. A gain detector determines a secondary path gain for at least part of a secondary path of a feedback loop. The secondary path may include the microphone, the sound transducer, and the acoustic path therebetween but does not include the non-adaptive canceling filter or the variable gain. A gain controller adjusts the in of the variable gain in response to the secondary path gain. The system use simple gain estimation and control to efficiently compensate for variations in the secondary path to provide improved stability and noise canceling performance.

An adaptive closed loop transmit power control system which does not require extensive factory calibration of power control loop bandwidths and feedback detect path gain settings over the power transition ranges, frequency bands of operation, temperature, and supply voltage is disclosed. The system automatically compensates for any gain or slope variations in the analog feedforward and feedback paths to maintain system stability and meet performance specifications. The system achieves this by using an adaptive digital signal processing (DSP) system architecture within the feedback path of this closed loop power control system. The system eliminates the need for extensive factory calibration of such parameters as loop bandwidths and feedback detect path gain settings over power transition ranges, frequency bands of operation, temperature, and supply voltage.

A spatial modulation method and transmitting and receiving apparatuses using the spatial modulation method in a MIMO system are provided. The spatial modulation method uses an index of an activated antenna and a signal modulation constellation as an information source. The spatial modulation method is applied to the transmitting apparatus. The receiving apparatus uses a spatial modulation detection method in which a channel path gain is repeatedly multiplied to detect the spatially modulated signal efficiently.

A wireless communication system having multiple interfering communication resources is considered. A power control procedure is based on assigning (Sl) a common control parameter to the considered communication resources, and using the control parameter together with a unique power control condition (S2) for determining the individual transmit power parameters of the communication resources. In particular, the idea is to determine, for each one of at least a subset of said communication resources, an individual transmit power parameter based on a power control condition implying that the total received power divided with the path gam of the communication resource should correspond to the common control parameter (S2). The determined transmit power parameters are then used for controlling (S3) the transmit powers of the corresponding communication resources. By using the proposed power control condition when determining the transmit power parameters, and then adapting the transmit data rates according to the resulting link quality, it is possible to maximize aggregate data rate for any given amount of total invested power.

For decreasing errors within an analog phase-locked loop, an all-digital phase-locked loop (ADPLL) with digital components and digital operations is used. The ADPLL may also be used for direct frequency modulation (DFM). By defining a proportional path gain of an ADPLL by a bandwidth and a reference frequency of the ADPLL, by a TDC gain, a DCO gain, a dividing ratio of a frequency divider, a gain of an amplifier or a combination thereof, the gain of the amplifier may be adjusted so that an optimal loop bandwidth of the ADPLL may be well calibrated. For achieving the aim of entirely digital of the ADPLL, the gains of the TDC and the DCO may be further adjusted in a digital manner.

A cellular system includes a first cell associated with a first base station, a second cell associated with a second base station, and a mobile radio currently served by the first base station. Distributed resource control may be used in which the first base station alone or in combination with the mobile station makes resource management decisions without having to involve a central controller. In ad-hoc networking, access points can manage resources in a distributed fashion. Relative path gain is determined for an uplink signal from the mobile radio. Relative path gain is based on a comparison of a first path gain related quantity for a mobile uplink signal to the second base station with a second path gain related quantity for the mobile uplink signal to the second base station. Uplink resources in the first cell are managed based on the relative path gain related quantity.

A system and method providing a wireless broadband connection between base stations and customer sites. The system includes indoor units, within the base stations and customer sites, that communicate across cables to outdoor units. The indoor units link to routers, switches and other devices and services. The outdoor units transmit and receive wireless data and send it to the indoor units. The indoor units control the functioning of the outdoor units by transmitting digital messages along the interface cables. The outdoor units report various detector values to the indoor units, which allows the indoor units to tune and adjust several functions within the outdoor units. Several embodiments for automatically calibrating the receive path gain in the base stations to compensate for the base station cable between the indoor unit and outdoor unit are described. In addition, anAn improved transmit power control technique which is not affected by modulation type, is also described.

The invention relates to a multi-path channel modeling method of an indoor single light source visible light communication system. In view of a small angle of view of an actual photoelectric detector (PD), the invention provides the multi-path channel modeling method according to an LED modulation symbol period. The method comprises a first step of giving a size of an indoor communication room, and characteristics of an LED and a PD, and calculating, by using an iteration method, time domain impulse responses of line of sight and multiple reflection signals between the LED and the PD in the single light source visible light communication system; a second step of determining a starting time point of multi-path channel modeling; a third step of giving a definition of inter-code interference, and determining a symbol sampling period of a receiving terminal; a fourth step of using a sum of impulse responses between sampling intervals as a gain of each path of the multi-path channel; and a fifth step of relative to the starting time point of modeling, dividing the sampling period by time delay of a finally received optical signal, and rounding up to an integer of a result of the previous division operation so as to be used as a total number of paths of the multi-path channel.