Functional description

The TV function is realized in the video module (VM). The TV picture is displayed on the Central Information Display (CID) and, depending on the vehicle equipment, on the rear monitor.

DVB-T and DVB-T RSE video modules: 

Each video module has one integrated analogue and one integrated digital TV tuner. The changeover between digital and analogue television takes place automatically, but can be switched off manually. The changeover from a digital to an analogue signal is indicated by the greater noise level of the analogue TV picture.

The TV tuner is installed in the video module. In the TV tuner, the video signal and the low-frequency audio signal are generated from the high-frequency aerial signal. The video module also contains a digital image processor that keeps the image stable even in reception areas with a weak signal and can eliminate image interference through filtering.

The sound signal is decoded in the video module and applied to the MOST as a digitized signal.

The video modules do not switch between the individual TV aerials but use all TV aerials simultaneously. For this purpose, the aerial signals are superimposed in the video modules. This results in a considerably improved television reception, even in analogue television.

As the base model, the DVB-T video module has two aerial inputs. The DVB-T RSE video module has three aerial inputs. ISDB-T video module (Japanese version only) 

The video module ISDB-T is exclusively designed for digital television, as digital television is standard in Japan.

A decoding card is required for the ISDB-T video module. It is installed by the authorized BMW dealer when the video module is purchased. The insertion slot for the decoding card is located in the video module opposite the electrical connections. It is used for registration with the operator. The ISDB-T video module is designed for TV mode while stationary and while driving. Unlike the DVB-T RSE, the video module does not require a third TV aerial and therefore has only 2 two aerial inputs.

DTMB video module (Chinese version only) 

The DTMB video module (Digital Terrestrial Multimedia Broadcast) has one analogue and one digital TV tuner integrated within it (analogue to the DVB-T). The DTMB video module is designed for TV mode while stationary and while driving. In the case of vehicles with Rear Seat Entertainment, all 3 aerials are connected. Otherwise, the third aerial input remains open.

Fig 1: Identifying Video Module Components

Courtesy of BMW OF NORTH AMERICA, INC.

The following graphic shows the slot for the decoding card on the reverse side of video module with the video module in the Japan version as an example.

Fig 2: Identifying Video Module

Courtesy of BMW OF NORTH AMERICA, INC.

The TV function is realized in the video module (VM). The TV picture is displayed on the Central Information Display (CID) and, depending on the vehicle equipment, on the rear monitor.

The video module modulates the high-frequency aerial signal (HF signal) that is fed over two or three aerial inputs, to a digital baseband signal.

During the process, both of the inputs are used for the reception of the actual dialled-in programs in the video module with the two aerial inputs. This mechanism, called MRC (maximum ratio combining), combines both reception paths. With it, an optimal mobile receiving power is achieved. Station searches are not performed in the background while driving (list of stations update). The video module performs the station searches when in standstill (driving speed below 5 km/h) during suitable reception conditions.

During suitable reception conditions, the video module with three aerial inputs uses the third aerial input for the station search in the background and thereby continuously updates the list of stations. In the process, the allocation between the aerial input and the reception paths for the station search (MRC function) of the video module is continuously reconfigured and is not firmly assigned.

All video modules try to maintain the currently selected station when changing to another service area (called: DAB/FM changeover). For the video module with two aerial inputs, the DAB/FM changeover can lead to a momentary break in reception due to the system architecture. For a video module with three aerial inputs, the DAB/FM changeover is virtually unnoticeable for the user.

For the Japanese version, the service 1-Seg (1 segment mode) is also supported in the ISDB-T.

Fig 1: Identifying Video Module Components

Courtesy of BMW OF NORTH AMERICA, INC.

The following graphic shows the slot for the decoding card on the reverse side of video module with the video module in the Japan version as an example.

Fig 2: Identifying Video Module

Courtesy of BMW OF NORTH AMERICA, INC.