CN101267424A - Modulation Method for UWB Wireless Communication Based on Frequency Sweep Pulse - Google Patents

Abstract

The invention relates to an ultra-wideband wireless communication modulation method based on sweeping pulses. It adopts binary quadrature keying and phase-shift keying joint modulation of frequency sweep pulse, combines quadrature keying and direct modulation, and improves the performance of binary quadrature keying modulation without introducing overlapping technology. The data transmission rate under the condition of sweeping pulses with the same time width avoids the intersymbol interference caused by pulse overlap, and opens up a broad field for the emergence of ultra-wideband modulation and multiple access methods based on sweeping pulses with better performance. space.

Description

Modulation Method for UWB Wireless Communication Based on Frequency Sweep Pulse

technical field

The patent of the present invention relates to an ultra-wideband wireless communication modulation method based on sweeping pulses, which belongs to the field of communication.

Background technique

Ultra-wideband (UWB) is a wireless communication technology that has emerged and developed rapidly in recent years, and is one of the current research hotspots in the world. A wireless communication system with a relative bandwidth greater than 25% or a system bandwidth greater than 500MHz in the 3.1GHz~10.6GH frequency band is called an ultra-wideband communication system. Different from the traditional wireless communication system with sine wave as the carrier, since the modulation bandwidth is extended to several GHz levels, the system can transmit data at a very high rate on the basis of occupying an extremely low power spectral density. At the same time, UWB also has the advantages of low cost, low energy loss, low capture rate, strong penetrating power, and multipath resistance. Therefore, the emergence of UWB technology provides a new technology without occupying the already crowded spectrum resources. voice and data communications. UWB technology has broad application value in short-distance wireless broadband access, indoor imaging precise positioning and military communication.

At present, there are mainly two physical layer technical solutions for UWB. One is based on radio impulse (IR) Direct Sequence Spread Spectrum (DSS) physical layer technical specification proposal; the other is based on multi-carrier OFDM physical layer standard technical specification proposal. The UWB system based on Direct Sequence Spread Spectrum (DSS) of Radio Impulse (IR) transmits and receives sub-nanosecond pulse signals to transmit information. It transmits and receives a narrow pulse signal with a pulse width of less than 1ns at a rate of tens of megabits per second, and the information is modulated into a precisely timed pulse train by pulse position modulation (PPM), pulse amplitude modulation (PAM) or other modulation methods. The other is a UWB system based on multi-carrier Orthogonal Frequency Division Multiplexing (OFDM), in which each sub-band has a bandwidth of 528MHz and is divided into 128 sub-carriers. transmitted on the carrier.

In addition, there is another UWB physical layer technology that is in the initial stage of research and has attracted the attention of some organizations and enterprises, that is, ultra-wideband communication based on frequency sweep pulse (Chirp). Chirp signal is a spread spectrum signal, which exhibits the characteristics of linear frequency modulation within a Chirp signal period, and the signal frequency changes linearly with time, because the frequency of the Chirp signal will "sweep" a certain amount within a signal period. The bandwidth, so the Chirp signal is also called "sweep signal". The sweeping characteristic of Chirp signal can be applied in the field of communication to express data symbols and achieve the effect of frequency spreading. This communication method using Chirp signal to spread spectrum is called Chirp Spread Spectrum (CSS).

Currently, Chirp-based UWB modulation methods mainly include binary orthogonal keying (BOK) and direct modulation (DM). Binary orthogonal keying modulation is to generate Up-Chirp and Down-Chirp signals at the transmitter to represent input data; while direct modulation uses a Chirp signal to express data symbols, and data symbols can be binary symbols or through various modulations The multi-ary notation obtained by the method. Due to the certain correlation between the Up-Chirp and Down-Chirp signals, the performance drops sharply in the indoor dense multi-channel environment. Although the direct modulation method can use the overlapping technology to increase the data rate, it also has relatively large intersymbol interference when the synchronization is not ideal.

Contents of the invention

The object of the present invention is to address the defects of the prior art and provide a modulation method for ultra-wideband wireless communication based on frequency sweep pulses, which is called binary orthogonal keying and phase shift keying joint modulation based on frequency sweep pulses, as follows Referred to as Chirp-BOK-BPSK modulation, without introducing pulse overlapping technology, it improves the data transmission rate under the condition of sweeping pulses with the same time width as BOK modulation, and avoids intersymbol interference caused by overlapping technology , At the same time, it also opens up a broad space for the proposal of a new Chirp-based UWB efficient modulation method.

The second object of the present invention is to provide a transmitter for realizing Chirp-BOK-BPSK modulation.

The third object of the present invention is to provide a Chirp-BOK-BPSK modulated signal receiver.

In order to achieve the above object, the present invention adopts the following technical solutions: the present invention adopts the joint modulation of Chirp-BOK-BPSK based on binary orthogonal keying and phase-shift keying based on frequency sweep pulse, and modulates the binary data information to the forward and reverse of frequency sweep pulse On the phase and positive and negative frequency modulation slopes, so the information volume of a frequency sweep pulse is 2 bits, which belongs to quaternary modulation. Suppose the binary data to be sent is b _n ∈ {-1, 1} (the subscript n represents the nth binary data, n ∈ (0, +∞)), where the duration of each bit of data is T _s /2, If the even-numbered data bit b _2n+2 of the binary data b _n modulates the positive and negative frequency sweep slope of the sending pulse, and the odd-numbered bit b _2n+1 of the binary data b _n modulates the positive and negative phases of the sending symbol, then the transmitter’s The output signal s(t) can be expressed as follows:

$\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{<span\; class="notranslate">\; \&infin;</span>}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$ $<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Where a(t) is the envelope of the frequency-sweeping pulse signal, where

f ₀ is the center frequency of the frequency sweep pulse, μ is the frequency sweep slope of the frequency sweep pulse, its value is equal to B/T _s , and t is time. According to the value of the binary data pair {b _2n+2 , b _2n+1 }, there are four possible states of the time domain waveform of the signal as follows:

$<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \}</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$

$<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \}</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$

$<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \}</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$

$<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \}</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$

Therefore, the Chirp-BOK-BPSK modulation is a quaternary modulation. The entire modulation process includes three steps: serial-to-parallel conversion, binary phase modulation, and binary quadrature keying modulation. The details are as follows:

Step 1: The transmitter first performs serial-to-parallel conversion on the binary data b _n to form two signals b _2n+1 and b _2n+2 respectively, and the time width of each data bit becomes twice the original one, that is, T _s .

Step 2: After completing the serial-to-parallel conversion, use one of the binary data b _2n+1 to modulate the positive and negative phases of the frequency sweep pulse to realize binary phase BPSK modulation in Chirp-BOK-BPSK modulation. That is, the underlined b _2n+1 item on the right side of the equal sign in formula (1) is rewritten as follows,

$\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{<span\; class="notranslate">\; \&infin;</span>}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{<span\; class="notranslate">\; \&OverBar;</span>}{\underset{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$ $<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula, b _2n+1 and b _2n+2 represent the odd bit and the even bit of the binary data b _n respectively, and other parameters are the same as those in formula (1).

Step 3: Use another channel of binary data b _2n+2 to modulate the positive and negative frequency sweep slopes of the frequency sweep pulses to realize binary quadrature keying BOK modulation in Chirp-BOK-BPSK modulation, that is, the right side of the equal sign in formula (1) has Underlined b _2n+2 term, rewritten as follows

$\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\overset{<span\; class="notranslate">\; \&infin;</span>}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\underset{<span\; class="notranslate">\; \&OverBar;</span>}{\underset{<span\; class="notranslate">\; \&OverBar;</span>}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="b"\; filenames="A20081003386500103.png"\; state="\{\{state\}\}">b</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}}}}\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span>$ $<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

After the above three steps, the two bits of information have been modulated onto the phase and slope of the frequency sweep pulse respectively, which completes the Chirp-BOK-BPSK modulation. The time width of the modulated frequency sweep pulse is T _s , and each modulated frequency sweep pulse carries two bits of data, so the data transmission rate is 2/T _s .

The transmitter of the present invention is a transmitter that realizes Chirp-BOK-BPSK modulation, as shown in FIG. 3 . Its main structure is to include a serial-to-parallel conversion circuit (31), which converts data into two-way parallel data, and realizes step 1 in the modulation method; positive and negative sweep slope selection circuit (32), according to the input binary data b _{2 +2} to select a sweep pulse (Up-Chirp) cos[2π(f ₀ +μt/2)t] with a positive sweep slope and a sweep pulse (Down-Chirp) cos[2π(f ₀ -μt/2)t] to realize step 3 in this modulation method.

The receiver of the present invention is a receiver for receiving Chirp-BOK-BPSK modulation signals, as shown in FIG. 4 . Its main structure includes two multipliers 4(1) and 4(2), two integrators 4(3) and 4(4), two sampling circuits 4(5) and 4(6) and a decision Device 4 (7), as shown in Figure 3. The multiplier and the integrator form a matched filter, the sampling circuit is used for sampling at the whole period of the frequency sweep pulse (t=nT _s ), and the decision unit judges and demodulates the sampled data to obtain the transmitted data. The entire receiver structure is shown in Figure 4.

The beneficial effects of the present invention are: the ultra-wideband modulation method provided by the present invention introduces the combination technology of binary orthogonal keying modulation and direct modulation based on frequency sweep pulse, and improves the frequency without introducing the overlap technology of frequency sweep pulse The data rate of pure BOK modulation or pure BPSK modulation also opens up a broad space for the emergence of ultra-wideband modulation and multiple access methods based on sweeping pulses with better performance.

Description of drawings

Figure 1 is the relationship between the frequency change of the sweep pulse and the binary data in Chirp-BOK-BPSK modulation. Wherein, 1 is the relationship curve of the sweep pulse frequency and time corresponding to the binary data +1, and 2 is the relationship curve of the sweep pulse frequency and time corresponding to the binary data -1.

Figure 2 shows the relationship between the phase of the frequency sweep pulse and binary data in Chirp-BOK-BPSK modulation. Wherein, 21 is the binary data +1, corresponding to the phase-time relationship curve of the sweep pulse, and 22 is the binary data-1, corresponding to the phase-time relationship curve of the frequency sweep pulse.

Figure 3 is a schematic diagram of a transmitter based on Chirp-BOK-BPSK modulation. Among them, 31 is a serial-to-parallel converter, the input is one serial signal and two parallel signals are output, and 32 is a fast selection circuit, according to the input binary data b _2n+2 , one of Up-Chirp and Down-Chirp is selected as Output, 33 is a frequency sweep pulse generating device for generating Up-Chirp pulses, 34 is a frequency sweep pulse generating device for generating Down-Chirp pulses, 35 is a multiplier, according to the input binary data b _2n+1 pair Sweep pulses for phase modulation.

Fig. 4 is a schematic diagram of a receiver based on Chirp-BOK-BPSK modulation. Among them, 41 is a multiplier whose input is the received signal r(t) and the local template signal φ ₁ (t), 42 is a multiplier whose input is the received signal r(t) and the local template signal φ ₂ (t) , 43 is an integrating circuit, integrating the product of r(t) and φ ₁ (t), 44 is an integrating circuit, integrating the product of r(t) and φ ₂ (t), 45 is a sampling circuit, at t =nT _s (n is an integer) moment the input of the integration circuit 43 is sampled, 46 is a sampling circuit, the input of the integration circuit 4 is sampled at t=nT _s (n is an integer), 47 is a decision device, its The input is the output of the sampling circuit 46 and the sampling circuit 47 to restore the original data b _n .

Fig. 5 is a time-compressed waveform diagram with a very high time-bandwidth product.

Fig. 6 is a time-diffused waveform diagram.

FIG. 7 is a time-domain waveform diagram of a Chirp-BOK-BPSK modulation signal. Wherein, (a) is an Up-Chirp waveform, (b) is an -Up-Chirp waveform, (c) is a Down-Chirp waveform, and (d) is a -Down-Chirp waveform.

Detailed ways

A preferred embodiment of the present invention is described as follows in conjunction with accompanying drawing:

Referring to Fig. 1 and Fig. 2, this UWB communication modulation method based on frequency sweep pulse adopts binary quadrature keying and phase shift keying of frequency sweep pulse to jointly modulate Chirp-BOK-BPSK, and binary quadrature keying BOK and The combination of direct modulation and DM improves the data transmission rate under the condition of frequency sweep pulse with the same time width as BOK modulation without introducing overlapping technology, and avoids the intersymbol interference caused by overlapping technology; specific operation steps as follows:

Chirp-BOK-BPSK modulation is a modulation method that transmits binary data information by different sweep slopes and phases of sweep pulses, and is a quaternary modulation. Suppose the binary data information input to the Chirp-BOK-BPSK modulator is: b _n ∈ {-1, 1}, n ∈ [0, +∞), and the time width of each bit of data is T _s /2; a( t) is a rectangular pulse, or a waveform that can reduce inter-symbol interference (such as triangular pulse, raised cosine pulse, Gaussian pulse, etc.), for the sake of simplicity, a(t) takes a rectangular waveform:

Because the Chirp-BOK-BPSK modulation is a quaternary modulation, before the data is input to the modulator, the binary data b _n is first serial-to-parallel converted, and the two signals of odd-numbered bits and even-numbered bits are respectively expressed as b _2n+1 , b _2n+2 and the time width of each data bit becomes twice the original T _s , then use b _2n+1 to modulate the positive and negative phases of the frequency sweep pulse, and b _2n+2 to modulate the positive and negative phases of the frequency sweep pulse Frequency sweep slope, the time width of the frequency sweep pulse is T _s , so that each modulated frequency sweep pulse will carry two bits of data, so the data transmission rate is 2/T _s . Therefore, the modulator has four different sweep waveform outputs according to the different input bits, which respectively represent the signal expressions when the data information is +1+1, +1-1, -1+1 and -1-1:

${\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}$

${\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}$

${\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="f"\; filenames="A20081003386500112.png"\; state="\{\{state\}\}">f</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}$

${\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; .</span>$

The transmitter of this embodiment is a transmitter based on binary quadrature keying and phase shift keying combined modulation of Chirp-BOK-BPSK based on sweep pulses, as shown in FIG. 3 . The Chirp-BOK-BPSK transmitter mainly consists of a serial-to-parallel conversion circuit (31), a positive and negative frequency sweep selection circuit (32), frequency sweep pulse generators (33, 34) and a multiplier (35). Among them, the serial-to-parallel conversion circuit converts the input binary data b _n into two channels b _2n+1 and b _2n+2 and doubles its time width; the positive and negative frequency sweep selection circuit selects according to the data b _2n+2 Positive frequency sweep slope pulse or negative frequency sweep slope pulse; the frequency sweep pulse generator is used to generate positive frequency sweep slope pulse and negative frequency sweep slope pulse; the main function of the multiplier is to realize the phase modulation of the frequency sweep pulse. The input is data b _2n+1 and a sweep pulse waveform generated by (33) or (34), and the output is the modulated Chirp-BOK-BPSK signal.

The receiver of this embodiment is a receiver based on binary quadrature keying and phase shift keying combined modulation of Chirp-BOK-BPSK based on sweeping pulses, as shown in FIG. 4 . The coherent demodulation module mainly implements the compression of the received modulated frequency sweep pulse. When the received pulse matches the local template signal, a frequency sweep pulse with a very high time-bandwidth product is generated as shown in (5), otherwise the received The pulses of will be diffused in time, as shown in Figure (6). The sampling circuit samples the compressed pulse at t=nT _s . The decision device makes a decision according to the two outputs of the sampling circuit and restores the original data b _n .

Claims (3)

1. ultra-broadband wireless communication modulation method based on scanning frequency pulse, it is characterized in that adopting binary orthogonal keying and phase-shift keying to unite modulation Chirp-BOK-BPSK based on scanning frequency pulse, binary orthogonal keying BOK is combined with direct modulation DM, when not introducing the overlapping technology, improved with BOK modulation and had message transmission rate under the scanning frequency pulse condition of identical time width, avoided the intersymbol interference that brings by the overlapping technology;

The concrete operations step is as follows:

Step 1: transmitter is at first to binary data b _nCarry out serial to parallel conversion, become two paths of signals and be expressed as b respectively _2n+1, b _2n+2And it is T that the time width of every circuit-switched data bit becomes original twice _s

Step 2: after finishing serial to parallel conversion, utilize wherein one road binary data b _2n+1The positive antiphase of modulation scanning frequency pulse realizes uniting the binary phase BPSK modulation of modulating Chirp-BOK-BPSK based on the binary orthogonal keying and the phase-shift keying of scanning frequency pulse.The output signal s of transmitter (t) as shown in the formula:

$s\left(t\right)=\underset{n=0}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{b}_{2n+1}a\left(t\right)\cos \left[2\mathrm{\&pi;}(f_0+b_{2n+2}\frac{\mathrm{\&mu;}}{2}t)t\right]$ $(n-\frac{1}{2})T_s<t<(n+\frac{1}{2})T_s$

A in the formula (t) is the envelope of scanning frequency pulse signal, here gets

f ₀Be the centre frequency of scanning frequency pulse, μ is the frequency sweep slope of scanning frequency pulse, and its value equals B/T _s, t is the time, b _2n+1With b _2n+2Represent binary data b respectively _nOdd bits bit and even bit bit;

Step 3: utilize other one road binary data b _2n+2The positive and negative frequency sweep slope of modulation scanning frequency pulse realizes that uniting the binary orthogonal keying BOK that modulates Chirp-BOK-BPSK based on the binary orthogonal keying of scanning frequency pulse with phase-shift keying modulates, the output signal of transmitter as shown in the formula:

$s\left(t\right)=\underset{n=0}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{b}_{2n+1}a\left(t\right)\cos \left[2\mathrm{\&pi;}(f_0+b_{2n+2}\frac{\mathrm{\&mu;}}{2}t)t\right]$ $(n-\frac{1}{2})T_s<t<(n+\frac{1}{2})T_s$

Through after above three steps, the information of two bits has been modulated onto respectively on the phase place and frequency sweep slope of scanning frequency pulse, has both finished the Chirp-BOK-BPSK modulation, and the time width of modulated scanning frequency pulse is T _s, and each scanning frequency pulse through ovennodulation carries two Bit datas, so message transmission rate is 2/T _s

2. the ultra-broadband wireless communication modulation method based on scanning frequency pulse according to claim 1, it is characterized in that described transmitter is for to unite the transmitter of modulating Chirp-BOK-BPSK based on the binary orthogonal keying and the phase-shift keying of scanning frequency pulse, its structure is: an output of a serial-parallel converter (31) is directly inputted to a multiplier (35), and another output is through a scanning frequency pulse generator (33 of selecting circuit (32) and two parallel connections fast, 34) produce Up-Chirp and Down-Chirp respectively, import described multiplier (35) afterwards.

3. the ultra-broadband wireless communication modulation method based on scanning frequency pulse according to claim 2, it is characterized in that with the matching used receiver of described transmitter for to unite the receiver of modulating Chirp-BOK-BPSK based on the binary orthogonal keying and the phase-shift keying of scanning frequency pulse, its structure is: two multipliers (41,42) respectively through two integrators (43,44) and two samplers (45,46) backs connect a decision device (47).

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