Abstract: The present invention is directed to a display for easily understanding time changes of communication conditions of channels using a plurality of sub-carriers. Layers corresponding to the plurality of channels are displayed along the time base in such a manner that width of each layer is determined in accordance with the number of sub-carriers used for each channel at any given time. Additionally, colors or patterns of each layer may be modified in accordance with modulation types or power levels of the corresponding layer. The relationship between colors or patterns of the layer and modulation types or power levels is displayed.

Abstract: PCR jitter is improved when writing an input stream TS having a packet with a PCR in a memory 10 and reading it at a high speed. An oscillator 44 oscillates a local clock signal having a frequency of a reference clock for the input TS and a counter 46 counts the local clock signal. When a PCR detection section 38 detects the PCR in the input TS, a latch circuit 42 latches a counted value of the counter and a PCR exchange section 40 exchanges the original PCR with a result of subtracting the latched count value from the PCR of the input TS.

Abstract: A signal analyzer repetitively memorizes waveform data of a signal under test to detect peaks P1-P6 of the waveform data. Waveform widths of the waveform data at a mask reference level, or a predetermined level down from the respective peaks, are evaluated as mask reference widths and then masks of the respective peaks are set using the mask reference level and mask reference widths. Hence the masks are automatically set, so a user can easily obtain time domain data and/or frequency domain data including characterizing portions in the signal under test.

Abstract: Selectable portions of a display on a display screen allow a user to select bits of a digital signal. A mode selection menu changes the bit selection to select bits in different ways. If an individual bit designation mode is selected, objects are displayed that correspond to the respective bits of the digital signal. A user selects the object corresponding to a desired bit by use of a mouse. After bit selection, an eye pattern, derived from only selected bits, is displayed. Additionally, jitter analysis results derived from only the selected bits are displayed.