摘要:
An object of the invention is to provide a diversity receiver and a reception system switching method capable of controlling diversity reception start and stop according to the switch condition responsive to person's liking and the use environment.An input section (109) allows the user to select and specify any of a diversity reception mode using two reception channels at all times, a single reception mode using a single reception channel at all times, or an automatic control reception mode for switching between the diversity reception and the single reception in response to the reception state of each mode, and a control section (107) determines a switching determination condition used in the automatic control reception mode according to mode selection information of other two modes. If the diversity reception selection frequency is large, the control section changes the determination condition to a determination condition for increasing the switching frequency to the diversity reception; if the single reception selection frequency is large, the control section changes the determination condition to a determination condition for increasing the switching frequency to the single reception.
摘要:
It is a theme of the present invention to provide a diversity receiving device and a receiving scheme switching method, capable of attaining a power saving by executing a switching between a diversity reception and a single reception with high accuracy. A receiving scheme switching portion (112) switches a receiving mode between a single reception and a diversity reception based on a receiving scheme switching threshold, updates the receiving scheme switching threshold based on the receiving rate calculated by a receiving rate calculating portion (110), switches the receiving mode into the single reception in which respective ones of antennas (101, 105), radio demodulating portions (102, 106), and decoding portions (103, 107) are employed respectively and also turns OFF respective power supplies of the remaining antenna (101 or 105), the remaining radio demodulating portion (102 or 106), and the remaining decoding portion (103 or 107) when the received quality calculated by the received quality calculating portion (111) exceeds the receiving scheme switching threshold, and switches the receiving mode into the diversity reception in which the antennas, the radio demodulating portions, and the decoding portions are employed in both branches when the received quality is below the receiving scheme switching threshold.
摘要:
It is a theme of the present invention to provide a diversity receiving device and a receiving scheme switching method, capable of attaining a power saving by executing a switching between a diversity reception and a single reception with high accuracy. A receiving scheme switching portion (112) switches a receiving mode between a single reception and a diversity reception based on a receiving scheme switching threshold, updates the receiving scheme switching threshold based on the receiving rate calculated by a receiving rate calculating portion (110), switches the receiving mode into the single reception in which respective ones of antennas (101, 105), radio demodulating portions (102, 106), and decoding portions (103, 107) are employed respectively and also turns OFF respective power supplies of the remaining antenna (101 or 105), the remaining radio demodulating portion (102 or 106), and the remaining decoding portion (103 or 107) when the received quality calculated by the received quality calculating portion (111) exceeds the receiving scheme switching threshold, and switches the receiving mode into the diversity reception in which the antennas, the radio demodulating portions, and the decoding portions are employed in both branches when the received quality is below the receiving scheme switching threshold.
摘要:
It is a theme of the present invention to provide a diversity receiving device and a diversity receiving method capable of making a diversity start not to cause receiving errors and also improving a sensitivity. There is a difference in a jamming wave level that is allowed to get the same received quality between the diversity reception and the single branch reception, so that a gain improving effect equivalent to a diversity gain is expected by the diversity reception in contrast to the single branch reception. Therefore, a dynamic range of the jamming wave from a transmitting portion (105) of a second radio system in a radio terminal is set smaller in expectation of the improving effect of such jamming wave resistance, and then a transmission control signal (S117) is acquired from a transmission signal controlling portion (106). Thus, the diversity reception is started before a start of transmission, and diversity control is applied adaptively without deterioration of the received quality. With such arrangement, NF of the system is improved at the same time, and as a result a receiving sensitivity in both the single branch reception and the diversity reception can be improved.
摘要:
It is a theme of the present invention to provide a diversity receiving device capable of reducing a power consumption to the utmost extent while keeping a predetermined received quality without measurement of an electric field strength and a fading pitch. A decision about whether or not the diversity reception is executed is made by sensing a received quality. Also, a diversity gain is reduced by a predetermined value by controlling the diversity gain in the diversity reception, then a receiving operation of a predetermined branch or a branch whose received quality is low is stopped when the received quality at that time is in excess of a previously set value, and then a supply of power to all circuit or a partial circuit of the branch whose receiving operation is stopped is shut down. Accordingly, a power consumption can be reduced to the utmost extent while keeping a predetermined received quality.
摘要:
It is a theme of the present invention to provide a diversity receiving device capable of reducing a power consumption to the utmost extent while keeping a predetermined received quality without measurement of an electric field strength and a fading pitch. A decision about whether or not the diversity reception is executed is made by sensing a received quality. Also, a diversity gain is reduced by a predetermined value by controlling the diversity gain in the diversity reception, then a receiving operation of a predetermined branch or a branch whose received quality is low is stopped when the received quality at that time is in excess of a previously set value, and then a supply of power to all circuit or a partial circuit of the branch whose receiving operation is stopped is shut down. Accordingly, a power consumption can be reduced to the utmost extent while keeping a predetermined received quality.
摘要:
A direct conversion receiver has: an I-low-pass filter 9 which has cut-off frequency switching device, switches over the cut-off frequency in accordance with the transmission rate, and eliminates high-frequency components from a modulated signal mixed with a first local signal; a Q-low-pass filter 10 which eliminates high-frequency components from a modulated signal mixed with the first local signal phase-shifted by 90 degrees; transmission rate detecting device 13 for detecting transmission rate information from transmission data detected by transmission data detecting device 12; and I- and Q-low-pass filter cut-off frequency controlling device 15 and 16 for generating I- and Q-control signals which control the cut-off frequency switching device, from the detected transmission rate. The cut-off frequencies of the low-pass filters are switched over in accordance with the transmission rate of reception.
摘要:
A direct conversion receiver includes a local oscillator for generating a first local oscillator signal having a variable frequency. A 90° phase shifter operates for shifting a phase of the first local oscillator signal by 90° to convert the first local oscillator signal into a second local oscillator signal. A first mixer operates for mixing a received RF signal and the first local oscillator signal. A second mixer operates for mixing the received RF signal and the second local oscillator signal. A first low pass filter processes an output signal of the first mixer. The first low pass filter has a controllable cutoff frequency. A second low pass filter processes an output signal of the second mixer. The second low pass filter has a controllable cutoff frequency. A demodulator recovers an information signal represented by the received RF signal from output signals of the first and second low pass filters. A frequency error detector operates for detecting an error between a frequency of a carrier of the received RF signal and the frequency of the first local oscillator signal in response to the information signal recovered by the demodulator. An oscillator controller operates for controlling the frequency of the first local oscillator signal in response to the error detected by the frequency error detector. A filter controller operates for controlling the cutoff frequencies of the first and second low pass filters in response to the error detected by the frequency error detector.
摘要:
A direct conversion receiver for providing a direct conversion of a radio frequency signal having a carrier frequency comprises a local oscillator for substantially equal frequency to the carrier, and a semiconductor integrated circuit mounting mixers and amplifiers for amplifying inputs to the mixer. The amplifiers amplify the local oscillation signals and/or radio frequency signal inputted from the outside of the semiconductor integrated circuit and supply the amplified signals to the mixers. The mixers mix these inputted signals and output the mixed signals to the outside of the semiconductor integrated circuit. By thus forming the receiver, radiation of the local oscillation signals to outside of the receiver and leakage inside thereof can be suppressed.
摘要:
In a receiver for effecting an intermittent reception operation, a reception unit including an antenna, a radio frequency amplifier, a local oscillator and a mixer, a received signal processing circuit for starting signal processing of a received signal from the reception unit after the passage of a predetermined time, a reception field level detection unit for detecting the level of the received signal and an automatic gain control unit for controlling the level of the received signal within the predetermined time and holding the controlled level after the passage of the predetermined time, are disposed in a plurality of stages.