ISDB-T/Tmm X-Series Measurement Application N6155A & W6155A

ISDB-T/Tmm Measurement Application

The ISDB-T/Tmm measurement applica­tion provides one-button, standard-based power and modulation analysis capabili­ties to help you with designing, evaluating, and manufacturing ISDB-T modulators, transmitters, amplifiers, tuners, and gap-fillers/repeaters. Used with the optional analog baseband IQ inputs in the PXA or MXA signal analyzer, it can provide you the flexibility of measuring signal quality and modulation accuracy with RF input or analog IQ input.

The ISDB-T/Tmm measurement applica­tion is just one in a common library of more than 25 measurement applications in the Keysight Technologies, Inc. X-Series, an evolutionary approach to signal analysis that spans instrumentation, measurements, and software.

The X-Series analyzers, with upgrade­able CPU, memory, disk drives, and I/O ports, enable you to keep your test assets current and extend instrument longev­ity. Proven algorithms, 100% code-compatibility, and a common UI across the X-Series create a consistent measure­ment framework for signal analysis that ensures repeatable results and measure­ment integrity so you can leverage your test system software through all phases of product development. In addition to fixed, perpetual licenses for our X-Series measurement applications, we also offer transportable licenses which can increase the value of your investment by allowing to you transport the application to multiple X-Series analyzers.

Key parameter setup

• Radio standard: ISDB-T, or ISDB-TSB, and ISDB-Tmm
• Channel bandwidth: 6/ 7/ 8 MHz for ISDB-T; 14.5 MHz for ISDB-Tmm
• Segment number: 13 segments for ISDB-T, 1 or 3 segments for ISDB- TSB, 33 segments for ISDB-Tmm
• FFT mode: 2K, 4K or 8K
• Guard interval: 1 /4, 1 /8, 1/16, 1/32
• Partial reception: On/Off
• Modulation: QPSK/16QAM/64QAM
• Input: RF or analog IQ (only available in the N9030A PXA or N9020A MXA) for signal quality and modulation ac­curacy measurements

ISDB-T, ISDB-TSB and ISDB-TB

Integrated services digital broadcasting (ISDB) is a Japanese standard for digital television (DTV) and digital radio used by the country's radio and television stations. ISDB-T and ISDB-TSB standards are the digital terrestrial broadcasting systems developed by Japan’s Association of Radio Industries and Business (ARIB). ISDB-T, as a terrestrial broadcasting system, has also been adopted by Brazil, where it is called ISDB-TB. ISDB-T and ISDB-TB both use an identical physical layer. ISDB-TSB is used for audio and data program trans­missions. The system and specifications of ISDB-TSB are similar to ISDB-T, except that the bandwidth is narrower and there are only one or three segments in the channel. Keysight’s ISDB-T measurement applica­tion supports measurement on both ISDB-T and ISDB-TSB standards.

ISDB-Tmm and AC

The new VHF band, 207.5 to 222 MHz, introduced in 2011, after the analog TV switch-off in Japan. The government announced that ISDB-Tmm (Terrestrial Mobile Multimedia) will be used for new multimedia service in this band. The ISDB-Tmm standard employs the concatenated transmission method which, combining blocks of the 13-segment (Type A) and the 1-segment (Type B), eliminates the need for a guard band, making it possible to apply it to various bandwidths. Figure 2 is an example of ISDB-Tmm frame structure consisting of two Type A super segments and one Type B super segment.

Auxiliary channel (AC) is used to convey additional information on modulation signal-transmission control, or earthquake alarm information. The earthquake infor­mation is transmitted using the AC of the center segment (segment No. 0).

Segment and layer in ISDB-T

ISDB-T supports hierarchical transmis­sion by introducing hierarchical layers, which means different services such as HDTV, multi-channel SDTV, and data, can be transmitted in one frequency channel. There are 13 OFDM segments in the ISDB-T transmission channel. Each layer consists of one or more segments which have their own transmission parameters (such as the inner coding rate, modulation scheme, and time interleaving length). A maximum of three layers can be provided, defined as Layer A, B, and C.

Partial reception

ISDB-T also supports partial receptions. Partial reception refers to the segment at the center of the transmission system. The range of frequency interleaving can be limited within the segment, so that narrow band (1-seg) receiver can receive services contained in the center segment. The gen­eral concept of hierarchical transmission and partial reception is shown in Figure 1.