摘要:
A technique for calibrating a N-port receiver, such as for example a 5- or 6-port receiver is proposed. The N-port receiver (1) comprises a first input (2) for a RF signal to be detected, a second input (3) for a RF signal originating from a local oscillator (4) and N−2 output terminals. Calibrating signals are generated on the basis of the RF signal supplied by the local oscillator (4). The calibration signals are fed to the first input (2) and/or the second input (3) of the N-port receiver (1). Calibration coefficients are calculated on the basis of the output signals generated by the N-port receiver (1) in response to the feeding of the calibration signals. The calibration signals are unmodulated signals and are only processed by means of a passive RF circuitry in the calibration device (100). The solutions according to the present invention allow a simple calibration of N-port receivers, which can be used as IQ demodulators or converters. Thereby a local oscillator (4) is used as a RF source for the calibration.
摘要:
A RF receiver for modulated RF signals based on a N-port junction (1) providing LO/RF isolation is proposed. N thereby is an integer larger than two, such that the N-port junction (1) can be preferably a three port, four port, five port and six port junction. The N-port junction (1) supplied with a first RF signal at a first input (2) and with a second RF signal originating from a local oscillator (2) at a second input (3). An isolation block (13) comprising an active circuitry (22) is comprised in the N-port junction for isolating the second input (3) from the first input (1). Thereby can be ensured that the LO signals are significantly attenuated at the RF port (2).
摘要:
A demodulator for modulated RF signals comprises a passive four port structure (1). The four port structure (1) has a first input (3) for supplying a modulated RF signal to be demodulated. A second input (2) is supplied with a RF signal from a local oscillator (21). Two output terminals are connected to power sensors (4, 5). The RF signal from the local oscillator (21) is supplied to the second input (3) of the four port structure (1) without being RF switched by an RF switch. The demodulator is particularly useful for modulation schemes with a finite number of magnitude states (nQAM modulation).
摘要:
A three port structure for the down conversion demodulation of a digitally modulated RF signal is proposed, wherein no RF switches are provided. The three port structure (1) has a first input (2) for the RF signal to be down converted and a second input (3) for a RF signal originating from a local oscillator (8). An output (4) of the three port structure (1) is supplied to a power sensor unit (5). The RF signal from the local oscillator (8) is modulated (7) before it is supplied to the three port structure (1).
摘要:
The present invention relates to a demodulation structure and method for downconverting and demodulating a digitally modulated signal So, with a local oscillator means (1; 5; 8) for providing a local oscillator signal Slo a mixer means (2) for mixing said local oscillator signal Slo and said digitally modulated signal S0 in order to obtain a mixed signal, a lowpass filter means (3) for lowpass filtering the mixed signal from the mixer means (2) and an analog-to-digital converting means (4) for converting the filtered signal from the lowpass filter means (3) into a downconverted and demodulated digital signal Sl, whereby the local oscillator signal is set in respect to the modulated digital signal so that the downconverted and demodulated digital signal output from the analog-to-digital converting means comprises to serially arranged information parts. The present demodulation structure provides a very simple structure with improved amplitude and phase imbalances.
摘要:
The present invention proposes a direct receiver technique based on one power measurement and time multiplexing of input signals. The proposed technique allows I/Q demodulation. The proposed technique bases on the passive linear three-port high frequency circuitry (1) having two RF signal input (2, 5) and one output port (3) attached to a power sensor (4). The signals output from the power sensor (4) is low pass filtered (17) and supplied to a DC interface. The proposed linear three-port circuitry (1) contains at least one RF switch and at least one passive circuit having at least one phase shifter functionality.
摘要:
A down converter for RF signals comprises one three port junction (7) having one input port six for modulated digital RF signals and two output ports (8, 9). The output ports (8, 9) are respectively connected to a power sensor (10, 11). The three port junction (7) comprises a power splitter (16) dividing the signal supply to the input terminal (6) of the two branches, processing means (17, 18, 19, 21, 22, 23, 24) for processing one of the branches and a four port junction device (20) for combining the two branches and for generating two output signals to be supplied to the output terminals (8, 9) of the three port junction (7). The processing means can comprise a delay unit (18) or alternatively a frequency divider (21), a plurality of filters (22, 24) and a frequency multiplicator (23).
摘要:
The present invention relates to n-port junction devices for processing modulated digital RF signals, n being an integer larger than 3, the n-port junction device comprising two RF input ports (4, 5), two passive signal-combining means (2, 3) connected to each other wherein respectively one of the passive signal-combining means (2, 3) is connected to one of the RF inputs (4, 5), and at least two power sensors (P1, P2) wherein each of the passive signal-combining means (2, 3) has at least an output port (6, 7) and each output port (6, 7) is connected to a power sensor (P1, P2). The two passive signal-combining means (2, 3) are connected with each other by means of a phase shifting element (10).
摘要:
A dual frequency band transceiver (10) is provided adapted to be operated into different transmission frequency bands. A control unit (8) controls a switching (6) between a first transmission frequency band FC1 and a second transmission frequency band FC2, wherein the control unit (8) changes correspondingly and simultaneously to the switching (6) in the first transmission frequency band FC1 and the second transmission frequency band FC2 between a first and a second channel bandwidth. The first and the second channel bandwidth satisfies the following equation: n*BC1=m*BC2, wherein BC1 and BC2 are the first and the second channel bandwidth, respectively, and n and m are an integer values starting with 1.
摘要:
A receiving apparatus (1) for receiving signals in a digital telecommunication system and a synchronizing method for synchronizing the receiving apparatus (1). The receiving apparatus (1) includes a receiver (2, 3) for receiving a reference symbol having at least two repetition patterns. One of the repetition patterns is phase-shifted in relation to the other. The receiving apparatus (1) is synchronized in the digital telecommunication system using the received reference symbol. The synchronization includes a cross correlation of at least one of the two repetition patterns within a cross correlation window having a predetermined length. In this manner, the performance and the accuracy of a cross correlation peak detection can be enhanced for improved synchronization.