摘要:
A quad 16 QAM transmission and reception methodology wherein a time domain pilot reference is advantageously associated therewith. There may be one or more such pilot references for each packet of multiple 16 QAM pulses. Depending upon the embodiment, each 16 QAM pulse can include a time domain pilot reference, or an estimated pilot reference for that pulse can be determined either by reference to pilot references in other pulses sharing the same packet, or by reference to pilot references for other previously received 16 QAM pulses corresponding to that same pulse.
摘要:
A diversity receiver that receives diverse modulated signals may produce a usable signal from the received modulated signals in the following manner. Two modulated signals, each including a desired component and an undesired component, are received by the diversity receiver, wherein each desired component includes an originally transmitted signal and each undesired component includes noise and interference. The diversity receiver estimates each desired and undesired component and produces the usable signal based on the estimated desired components and the estimated undesired components.
摘要:
A base site (104) generates a pseudo-random signal based on at least one system parameter known to both the base site and a communication unit (112). The base site (104) then transmits the pseudo-random signal to the communication unit via an idle communication resource (102). Upon receiving the pseudo-random signal, the communication unit (112) determines at least one characteristic of the idle communication resource (102) using the pseudo-random signal.
摘要:
The ratio of peak power level to average power level in a power amplifier used in a QAM communication system transmitter can be reduced by preselecting magnitudes and phase angles of complex-valued pilot symbols used in multi-channel, N-level QAM.
摘要:
In a digital communication system in which pulse-shape filtered sync, pilot, and data symbols, arranged in successive time slots, modulate sub-channel carriers via sub-channel mixers to form sub-channel symbol streams for combination into a composite signal for transmission, deterministic portions of each time slot are rendered identical by determining phase difference of sub-channel carriers and rotating the phase of each sub-channel symbol stream by an amount equal to the phase difference, but with opposite sign.
摘要:
A range equalization transceiver system (100) for increasing efficiency of a continuous duty communications link includes a first transceiver (105) for transmitting data traffic over a broadband traffic channel and a second transceiver (107) for determining routing information using a discovery channel based on link quality. A controller (103) is used for interpreting routing information from the second transceiver (107) where the controller (103) selects a transmitting scheme based on data traffic conditions on both the broadband traffic channel and link quality channel for sending data over a wireless network.
摘要:
A wireless communication system (100) that includes a plurality of base sites (101-103) employs a method and apparatus for determining a location of a communication unit (107) in the system. Upon transmission of an information signal (109) by the communication unit, each of the base sites receives the transmitted information signal. A serving base site (e.g., 103) determines a stream of information symbols from the information signal, derives timing information based on the information signal and the stream of information symbols, and conveys the stream of information symbols preferably to at least two non-serving base sites (101-102). The non-serving base sites determine respective timing information based on the information signal received from the communication unit and the stream of information symbols received from the serving base site. The location of the communication unit is then determined by either a base site or a stand-alone processing device (105) based on the serving base site's and non-serving base site's timing information.
摘要:
In a diversity reception communication system (200), a method is provided for recovering data symbols (213) from a transmitted signal. Multiple signals representing the transmitted signal are received via corresponding multiple reception paths (201, 202). For each reception path, values are determined for noise (206), channel quality (207), and for a weighting factor (209) as a function of the channel quality. The signals are processed using diversity combining (212) which includes the weighting factor (209) for each reception path, to provide a resultant signal that more likely represents the transmitted signal than any of the received signals alone. The data symbols (213) are recovered from the resultant signal.
摘要:
A diversity receiver that receives modulated signals may determine signal usability of the received signals in the following manner. A modulated signal that includes a desired component and an undesired component is received in each receiver branch of the diversity receiver, wherein the desired component includes an originally transmitted signal and the undesired component includes noise and interference. Each receiver branch estimates the desired and undesired components and processes the modulated signal with a channel gain/phase estimator, a complex conjugator, and a complex mixer to produce a complex output. The complex output of each receiver branch is derived independently of the undesired component and combined to produce a diversity resultant. The diversity receiver estimates the signal usability of the diversity resultant based on the estimated desired components and the estimated undesired components.
摘要:
A method of low-splatter peak-to-average reduction for a linear communication system includes the step of sampling (1201) an input signal at a first rate, yielding a plurality of input samples. When at least one (1401, 1403, and 1405) of the plurality of input samples is above a first threshold, a local maximum (1401) is determined (1207) from among the plurality of input samples. At least one value (1407 and 1409) is interpolated (1207) between the local maximum and at least one sample (1405) adjacent to the local maximum. The at least one value and the local maximum are compared (1211) to determine which has the highest magnitude. The value having the highest magnitude (1407) is compared (1213) to a second threshold. When the value having the highest magnitude (1407) is above the second threshold, an attenuating window is centered (1505) at the value having the highest magnitude and applying (1507) the attenuating window to at least some of the plurality of input samples.