Signal processing device and signal processing method

Signal processing device and method include at least two codec units configured to operate in a plurality of modes of a coding/decoding/tandem free operation for data transmitted on a respective allocated channel. A control unit is configured to control the at least two codec units. The control unit includes a detection unit, a judging unit, and a commanding unit. The detection unit is configured to detect a request for activating a codec unit. The judging unit is configured to judge whether a resulting required signal processing power for all activated codec units exceeds a predetermined threshold level of an overall signal processing power. The commanding unit is configured to command, if the judging unit takes a positive judgment, at least one of the activated codec units to operate in such a mode that the resulting signal processing power for all activated codec units does not exceed the predetermined threshold level.