Abstract: A spread spectrum radio transmission digital mobile communication device having RAKE receiving functions. By adding an arrangement of an adaptive antenna to control directivity of a receiving antenna to the spread spectrum radio transmission digital mobile communication device, it is possible to decrease influence of a co-channel interference wave and influence of a delay wave having a delay time smaller than chip time width in a diffusion signal, as not achievable by RAKE receiving functions.

Abstract: The present invention provides a spread spectrum radio transmission digital mobile communication device having RAKE receiving functions and capable of decreasing influence of a delay wave having a delay time smaller than chip time width of a diffusion signal.

Abstract: A receiving system comprises a plurality of receiving branches 1, 2, - - - n each including an adaptive antenna. A variable gain controlled amplifier 31, 32, - - - 3n is provided in each receiving branch 1,2, - - - n for setting an amplification factor of a receiving signal in each receiving branch. Automatic gain control unit 7 inputs receiving signals from the plural receiving branches 1,2, - - - and n at predetermined sampling intervals and controls the amplification factors of the variable gain controlled amplifiers 31, 32, - - - 3n. An adaptive antenna processing unit 8 performs an adaptive antenna processing based on the receiving signals sent from the plural receiving branches 1,2, - - - n. A timing control device 71, 72 or 73 allows the automatic gain control unit 7 to renew the amplification factor of each variable gain controlled amplifier 31, 32, - - - 3n in response to each elapse of a predetermined interval longer than the sampling interval of the automatic gain control unit 7.

Abstract: An automatic gain control apparatus includes a variable gain amplifier 5 to amplify a signal with an amplification factor and a gain controller 6 to control the amplification factor of the variable gain amplifier 5. A gain limiter 7 is provided for restricting the magnitude of the amplification factor within a predetermined range. The amplification factor therefore does not vary largely, even immediately after the input signal level is suddenly changed due to a switching of a transmitter antenna or a carrier frequency. Thus, it is possible to quickly respond to the change of input signal without requiring a large dynamic range in the circuit following the automatic gain control apparatus.

Abstract: A stored instructions executing type timing signal generating system for flexibly generating a plurality of control timing signals having many changing points includes an instruction memory for storing a series of instructions stating contents of changes and relative time intervals between the changes of a series of control timing signals and a circuit for triggering the instruction execution by the absolute time for the series of instructions, so that after a first instruction has been executed, each succeeding instruction is sequentially executed on the basis of a relative time interval before the execution of a next instruction stated in the instructions, thereby to generate the control timing signals. The number of changing points of the control timing signals is basically dependent only on the number of words of the instruction memory, and therefore the plurality of control timing signals having many changing points can be generated easily.