100km TDD transmissão sem fio de dados de vídeo bidirecional

100km TDD bidirectional video data wireless transmission Appearance

Histórico de versões

Data	Versão	Descrição da modificação
20231219	V1.0	Versão inicial
20240315	V2.0	Modify the weight dimensions, modify the total data  in Table MCS & Sensibilidade
20240405	V3.0	Add multiple sets of coexistence switches. Modify the serial-to-network configuration mode. Modify the ID number length and modify the English words of background noise detection. Added the frequency matching function

Visão geral

Vcan1933-8-Watt PA is a self-developed TDD bidirectional graph integrated wireless transmission device. The product has the functions of real-time interference detection, seleção de frequência adaptativa, fluxo adaptativo, retransmissão automática, and automatic power control, o que melhora muito a capacidade de anti-multipath e anti-interferência, e tem as características de alta confiabilidade, boa estabilidade, e baixo atraso.

Este produto é adequado para combate a incêndios, inspeção, monitoramento, e outros cenários,  and can transmit 100KM under good air-to-ground vision. 

Product Characteristics

• Support long-distance transmission: 4M code flow can be transmitted up to 100km.
• Supports large bandwidth transmission: Up to 17Mbps@10MHz.
• Supports automatic repeater transmission: Supports automatic trunk addition.
• Supports multi-interface design: The device has two network ports and four serial ports, supporting RS232/TTL/RS422/SBUS.
• Supports automatic frequency selection: Automatic detection of interference signals, real time selection of the optimal frequency point.
• Supports automatic retransmission: Automatic retransmission of burst error data improves data reliability.
• Supports adaptive stream: The channel modulation mode is automatically adjusted according to the signal quality in real time.
• Supports automatic power control: Close range automatic adjustment of transmission power, reduce power consumption.
• Suporta seleção automática de antena: De acordo com a situação de oclusão, the optimal antenna transmission is selected in real time.
• Supports the coexistence of multiple set: Support up to 6 sets of equipment at the same time fixed frequency use.
• Supports the frequency matching function: Software can be used to configure the frequency and hardware key frequency.

Especificação

Parâmetro do sistema	Índice técnico
Equipment model	Vcan1933-8W
Working frequency	1350~1470 MHz
Radiofrequência	2T2R
Potência de transmissão	39dBm (8-watt PA)
Distância de transmissão	100km (LOS ar-solo)
Largura de banda do canal	10MHz
Modo de modulação	QPSK/16QAM
Recebendo sensibilidade	See Table (MCS & Sensibilidade)
Velocidade	17Mbps@16QAM3/4
Criptografia de comunicação	AES256
Atraso de transmissão	≤10ms
Interface de radiofrequência	SMA*2
Equipment interface	XT30PW-M
Equipment interface	100Mbps Ethernet*2
	TTL/RS232*2
	RS422*1
	SBUS/TTL*1
Overall power consumption	≤48W@4Mbps(Air uint)
	≤12W@1Mbps(Ground uint)
Dimensão(L*W*H)	163*77*25milímetros
Peso	340g
Tensão de trabalho	DC22~30V,Valor típico: +24V@2A
Temperatura de trabalho	-40~+75℃

MCS & Sensibilidade (10MHz)
No.	MCS	Total uplink and downlink  throughput (Mbps)	Sensibilidade (dBm)
1	QPSK1/3	4.0	-99
2	QPSK1/2	5.8	-98
3	QPSK2/3	7.1	-97
4	QPSK3/4	8.2	-96
5	16QAM1/3	8.0	-96
6	16QAM1/2	11.6	-95
7	16QAM2/3	14.3	-93
8	16QAM3/4	16.4	-91

Product dimension and weight

Dimension diagram

Dimension and weight

• Dimensão (L*W*H): 163mm*77mm*25mm(including SMA 10mm)
• Peso : 340g

Product interface definition

Interface diagram

The interface of the Vcan1933-8W device includes the XT30PW-M power interface and J30J-25pin data interface. The interface has RS232/TTL*2, RS422*1, SBUS/TTL*1 and 100 Mbit/s Ethernet*2.

Definição de interface

Interface de energia: XT30PW-M. Faixa de fonte de alimentação: DC22-30V Typical value:24V@2A 

Linear  order.	Nome do alfinete	Definição de interface	Descrição da interface	Signal  direction
1,2,3,4	GND	Chão	Chão
5	422UMA	Serial port 3 RS-422	Receiving data RX+	EU
6	422B		Receiving data RX-	EU
7	422Z		Transmitting data TX-	Ó
8	422S		Transmitting data TX+	Ó
9	TXD_A	Serial port 1 RS232/TTL	Transmitting data TX	Ó
10	RXD_A		Receiving data RX	EU
11	TXD_B	Serial port 2 RS232/TTL	Transmitting data TX	Ó
12	RXD_B		Receiving data RX	EU
13	GND		Porta serial 2 chão	Ó
14	SBUS /TTL TX	Serial port 4 SBUS/TTL	SBUS/TTL sending	Ó
15	SBUS /TTL RX		SBUS/TTL receiving	EU
16	SBUS/TTL GND		SBUS/TTL ground	Ó
17	TX1P+	Porta de rede 1	Transmitting data TX+	Ó
18	TX1M-		Transmitting data TX-	Ó
19	RX1P+		Receiving data RX+	EU
20	RX1M-		Receiving data RX-	EU
21	GND	Chão	Porta serial 1 chão	Ó
22	TX2P+	Porta de rede 2	Transmitting data TX+	Ó
23	TX2M-		Transmitting data TX-	Ó
24	RX2P+		Receiving data RX+	EU
25	RX2M-		Receiving data RX-	EU

• Observação 1: Signal direction I indicates radio input and direction O indicates radio output.
• Observação 2: When using the serial port 1/2 of the device, please check whether it is TTL level or RS232 level.

EUndicator Meaning

The RSSI light represents the strength of the received signal
Number of RSSI energy lights on	Received energy dBm
3 RSSI lights on	about -50dBm
2 RSSI lights on	about -80dBm
1 RSSI light on	about -95dBm

Tipo de módulo	Modo	Vcan1933-8W light status
		PWR	SYNC	LAN 1 LAN 2	RSSI 123
mestre	Un-sync	Ligado	Flashing	Data sending and  receiving, piscando	Desligado
mestre	Sincronizar	Ligado	Steady on	Data sending and  receiving, piscando	Proportional to the  strength of the received  signal
escravo	Un-sync	Ligado	Flashing	Data sending and  receiving, piscando	Procurando
escravo	Sincronizar	Ligado	Steady on	Data sending and  receiving, piscando	Proportional to the  strength of the received  signal

When the master and slave devices are not synchronized, the PWR indicator of the  master and slave devices is steady on, the SYNC indicator is blinking, and the RSSI  indicator of the master device is off. The RSSI of the slave device will always be in the  search state. After the master/slave synchronization, the SYNC indicator of the  master/slave is steady on. The master-slave RSSI lamp displays the received signal  energy intensity. When the network port is sending or receiving data, the master and  slave devices correspond to LAN1, and the LAN2 indicator blinks.

More information about the product

TDD (Duplexação por Divisão de Tempo) is a communication technique used in wireless systems where the uplink (transmitting data from the ground control station to the drone) e downlink (transmitting video and data from the UAV to the ground receiver or GCS) share the same frequency channel but operate in different time slots. This allows bidirectional communication without requiring separate frequency bands for each direction.

TDD Protocol Optimization

• Ensure proper time slot allocation between uplink (sending data) e downlink (receiving data) for efficient bidirectional communication.
• Adaptive TDD allows dynamic allocation based on data traffic needs.
• Useful in applications where uplink and downlink traffic are asymmetric (por exemplo, video streaming).

Comparison Between TDD and FDD

Recurso	TDD	FDD
Spectrum Usage	Single frequency band	Separate bands for uplink and downlink
Traffic Adaptability	Highly adaptable to asymmetric traffic	Fixed uplink/downlink ratio
Equipment Complexity	Lower cost and simpler hardware	Requires duplexers, increasing cost
Channel Reciprocity	Sim, supports advanced techniques like beamforming	Não
Interferência	Requires strict synchronization	Less prone to interference

TDD is widely used in modern communication systems, including those requiring long-range bidirectional video transmission due to its efficiency and flexibility.

Power and Size Constraints:

• Lightweight hardware to minimize the impact on drone flight performance.
• Low-power consumption design to maximize drone battery life.
• Compact form factor to fit within the drone’s payload.

Sistema de Antena:

• On Drone: Fiberglass omnidirectional or small directional patch antennas.
• Estação Terrestre: High-gain parabolic, Yagi antennas or flat panel antennas with tracking systems for long-range communication.

Aplicações

1. Surveillance and Security: Real-time video streaming from drones for law enforcement or border control.
2. Radiodifusão: High-definition aerial footage for live events or media.
3. Agricultura: Monitoring crops and livestock over vast areas.
4. Resposta a desastres: Sending live video from disaster sites for better coordination.

o faixa de transmissão of an 8-watt power amplifier (PA) depends on a variety of factors, incluindo:

1. Banda de frequência: Higher frequencies experience more signal loss over distance (higher free-space path loss).
2. Antenna Gain: The type and gain of the antenna at both ends (transmitter and receiver) significantly impact the range.
3. Condições Ambientais: Factors like terrain, edifícios, weather (chuva, névoa), e linha de visão (LoS) can affect range.
4. Modulation Scheme and Data Rate: More complex modulation schemes (por exemplo, QAM) and higher data rates may reduce effective range due to higher sensitivity to signal degradation.
5. Sensibilidade do receptor: The ability of the receiver to detect a weak signal at a specific distance.