Abstract: In a compressed mode, a spread spectrum communication device interleaves bit units across multiple frames using an interleaver, reduces the spreading factor using a framing/spreading unit, outputs the compressed mode frames at a predetermined compressed mode frame timing, and increases the average transmission power in the compressed mode at a radio frequency transmitter. Furthermore, a handover between different frequencies is carried out by establishing synchronization to another frequency carrier, based on a first search code and a second search code which have been detected, and moreover, a handover between different communication systems is carried out by establishing synchronization to a GSM, based on an FCCH and a SCH which have been detected.

Abstract: Conventionally, if the number of transmission antennas is greater than that of reception antennas, different signals simultaneously transmitted from the transmission antennas cannot be separated from one another at the receiving end, resulting in a significant degradation of received-signal quality. A transmitter and a receiver each have a plurality of antennas. The transmitter transmits a pilot signal. The receiver receives the pilot signal to calculate transmission-related information corresponding to the pilot signal, and then selects, based on this calculated information, a signal to be sent to and utilized by the transmitter. The receiver then informs the selected signal to the transmitter. The transmitter selects, from the informed signal, transmission antennas and uses them to transmit information signals, so that a signal separation can be easily performed at the receiving end.

Abstract: In the mobile radio communication system where the UMTS and an another system coexist an idle slot for observing the frequency component of another system is inserted in one superframe of UMTS. The duration of this idle slot is at most half of the duration of one frame that form the superframe and it is inserted at an interval of a specified number of frames. Therefore, the frequency component of the another system can be observed securely from the UMTS. Further, deterioration of interleaving performance of the compressed mode frames during such observation can be suppressed.

Abstract: A finished pattern that will be formed based on a design layout pattern in a semiconductor manufacturing process is predicted, and the outline of the predicted finished pattern is converted into a polygon. On the other hand, test reference patterns are formed based on the design layout pattern. A pattern distortion in the predicted finished pattern is detected by comparing the polygonized predicted finished pattern with the test referencepatterns. In converting the predicted finished pattern into a polygon, the number of apices of the polygon is reduced. Two kinds of test reference patterns are formed: an upper limit test reference pattern obtained by reducing the design layout pattern and defining an allowable upper limit and a lower limit test reference pattern obtained by enlarging the design layout pattern and defining an allowable lower limit.

Abstract: A semiconductor laser includes a lower cladding layer, an active layer, a first upper cladding layer, an etch-stopping layer, a second upper cladding layer, and a contact layer successively laminated on a substrate, a ridge waveguide formed by selectively etching the second upper cladding layer and the contact layer with the use of a stripe-like insulating film as a mask to form a ridge, an AlAs oxide layer on the substrate and a second electrode on the substrate. Incorrect positioning does not occur between the ridge waveguide and a first electrode, reliability is improved, and the distribution of effective refractive index transverse to the resonation of the laser is reduced. A detailed method of fabricating this semiconductor laser is also provided.

Abstract: A differential amplifier receiving a first input signal and a second input signal, respectively, and amplifying voltage difference between the first and second input signals to output an output signal includes a first source follower circuit receiving an external data signal as the first input signal, and having an output node; a second source following circuit having a constant current source FET and receiving a reference voltage as the second input signal; and a bias circuit providing a signal having the same phase as the data signal from the output node of the first source follower circuit and inputting that signal to a gate terminal of the constant current source FET of the second source follower circuit.