Abstract: The present invention relates to a spelling and encoding method for ideographic symbols, such as Chinese characters. The spelling method can provide first and second components for identifying first and second groups of ideographic symbols, wherein the two groups can have at least one common ideographic symbol correlating with the two components. For example, the two components can be a Chinese Pinyin spelling and a Four Corner Numerical Index, respectively, which can each identify a group of Chinese characters and be combined to identify one or more characters. The spelling method can further provide a third component to differentiate a plurality of ideographic symbols common to the two groups to uniquely identify each common symbol. In one embodiment, an alphanumeric spelling can be provided to uniquely identify each ideographic symbol. The encoding method can encode various alphanumeric representations of the ideographic symbols by the 7-bit ASCII standard code.

Abstract: A multiplex radio transmission system is provided with facilities for initiating protective switching from a working channel to an idle channel of the system when the signal to interference ratio on the working channel falls below a predetermined threshold value. A precise square-law detector derives, from the separate information and interference components of a signal on the working channel, a DC component and a difference-beat AC component which are processed to yield a quantity indicative of the desired signal to interference ratio. When such ratio falls below the predetermined threshold value, switching to an idle channel occurs in a manner similar to conventional signal-to-noise dependent protective switching arrangements.