One of most popular and cheap hadrware in SDR is RTL-SDR, this dongle can I/Q sample with resoulotion 8bit ADC, it can too used DVB-T dongle, in this blog post we describe how RTL-SDR can received DVB-T signal and show in VLC media player?
HackRFOne is another SDR hardware that i worked with it, It can not show DVB-T from dongle based driver like RTL-SDR. we want to in this post discuss how RTL-SDR can show DVB-T singal in vlc? it solution is a SDR based or hardware based.That RTL-SDR that we have is NooElec NESDR XTR Tiny SDR & DVB-T USB Stick (RTL2832U + E4000) w/ Antenna and Remote Control .Now we can from featured image of blog post it has two chip RTL2832U & E4000EQG you can find data sheet of them easily on net.You can see schematic RTL-SDR:
Fig1: Schematic RTL-SDR
One of Question RTL-SDR has bandwith about 3MB how can show DVB-T TV?
We know bandwidth DVB-T signal is 8MB, that we soon share GQRX showing spectrum DVB-T signal here. For getting answer we should examine circuit and datasheep of two chips that used RTL-SDR.
E4000 chip is MULTI‐STANDARD CMOS TERRESTRIAL RF TUNER. The E4000 is a highly integrated multi‐band RF tuner IC implemented in CMOS, ideal for digital TV and radio broadcast receiver solutions. The digitally programmable multi‐band tuner architecture allows the user to re‐configure the RF front end for different broadcast standards.
- DVB‐T (174‐240MHz, 470‐858MHz)
- CMMB Terrestrial (470‐858MHz)
- D‐TMB (174‐240MHz, 1452‐1492MHz)
- ISDB‐T (470 – 862MHz)
- DVB‐H (470 – 858MHz, 1672‐1678MHz)
- T‐DMB (174 – 240MHz, 1452 – 1492MHz)
- DAB/DAB+ (174 – 240MHz, 1452 – 1492MHz)
- GPS L1 band (1575MHz) – (with additional LNA)
- FM radio(64-108MHz)
You can blockdiagramE4000 in below, in RF input it has LNA, that effect good receiver on RTL-SDR. It is Great chip You can control Broadcasting RF Band By programble way .
Fig2:Block Diagram E4000
An other chip is RTL2832U is a high-performance DVB-T COFDM demodulator that supports a USB 2.0 interface. The RTL2832U complies with NorDig Unified 1.0.3, D-Book 5.0, and EN300 744 (ETSI Specification). It supports 2K or 8K mode with 6, 7, and 8MHz bandwidth. Modulation parameters, e.g., code rate, and guard interval, are automatically detected.
The RTL2832U supports tuners at IF (Intermediate Frequency, 36.125MHz), low-IF (4.57MHz), or Zero-IF output using a 28.8MHz crystal, and includes FM/DAB/DAB+ Radio Support. Embedded with an advanced ADC (Analog-to-Digital Converter), the RTL2832U features high stability in portable reception.
The state-of-the-art RTL2832U features Realtek proprietary algorithms (patent-pending), including superior channel estimation, co-channel interface rejection, long echo channel reception, and impulse noise cancellation, and provides an ideal solution for a wide range of applications for PC-TV, such as USB dongle and MiniCard/USB, and embedded system via USB interface.
- COFDM complying with Nordig Unified 1.0.3, D-book 5.0, and ETSI 300-744
- Supports multiple IF frequencies (4.57MHz or 36.167MHz) and spectrum inversion
- Includes Radio Support (FM/DAB/DAB+)
- Includes ISDB-T(SBTVD-T) 1-Seg
- Supports Zero-IF input
- Single low-cost crystal for clock generation (±100ppm)
- Automatic transmission mode and guard interval detection
- Impulse noise cancellation circuits
- Automatic carrier recovery over a wide range offset (±800KHz)
- Superior performance with pre/post/long echo profiles
- Embedded adjacent and co-channel interference rejection circuit
- Delayed AGC with programmable Take-Over Point (TOP)
- 7-bit ADC for RF signals level measurement
- Hardware MPEG-2 PID filters
- Infra-red port for remote control and wake-up, protocols supported are:
- Microsoft RC6 protocol
- NEC, Sony, SIRC, RC-5 protocol
- Eight general purpose I/O ports
- USB 2.0 Interface
- Supports USB Full/High speed
- Configurable vendor information via external EEPROM
- Passes USB-IF certification
- Signal 3.3V external power is required
- 48-pin QFN (6×6 mm2) Green Package
Now We concluded that RTL-SDR can receive DVB-T signal by hardware based, SO HackRF one has not any chip demodulator for DVB-T so HackRFOne can not show video TV as DVB-T dongle, we should for receiving DVB-T signal with HackRFOne using GnuRadio.
How I can use RTL-SDR as DVB-T dongle?
It is easy you can download driver for windos from this link, in linux from kernel 2.6 it is installed default. You can show playing video DVB-T with VLC in below video.