A spread spectrum signal demodulating method whereby spread-code synchronous acquisition and carrier synchronous acquisition are performed using FFT at high speed, wherein a received signal, of which the carrier wave is modulated with a signal obtained by spectrum-spreading data with a spread code, is subjected to the FFT and the result of the FFT is stored in a first memory. The coder is arranged to code the symbols using a code matrix, which can be expressed as a sum of 2K elements, in which each element is a product of a symbol or symbol complex conjugate to be transmitted and a N\xd7N representation matrix of a complexified anti-commutator algebra, extended by a unit element, and in which each matrix is used at most once in the formation of the code matrix. Under normal operating condition, the ESD detection circuit will not trigger the ESD protection device, and therefore the component used in the circuit will not have the gate-oxide reliability issue and also will not generate undesirable leakage current. In some implementations, a geo-location and an accuracy determination may be used to determine all required sample regions in order to ensure that a primary user is not present in a particular location. The control element for controlling the movements of the fingers include a control piston which can slide inside the rod of the jack and which is associated with a bistable actuator of the fingers, capable of moving between a retracted position and an active position in which the fingers are deployed with the application of successive pressure pulses in the jack elements. The levels of human immunodeficiency virus are measured in CD4CD8 double negative cells.