TW201633728A - Communication system and method - Google Patents

Abstract

A communication system includes a packet stream unit, a mapping unit, and a transmission unit. The packet stream unit is configured to receive a 4-bit packet stream and convert the 4-bit packet stream to a 6-bit packet stream. The mapping unit is configured to map the 6-bit packet stream to multiple ternary digit streams and map at least one idle symbol to the ternary digit streams according to at least one predetermined digit. The transmission unit is configured to transmit the ternary digit streams to a remote communication device via a cable.

Description

Communication system and method

The present disclosure relates to a communication system and method, and more particularly to a communication system and method for transmitting data by cable.

In order to improve the development of the network, the Institute of Electrical and Electronics Engineers (IEEE) sets standard specifications for network transmission at different rates and different media. Under the innumerable research efforts, the transmission speed of cable cables has been high. One billion bits per second (Gbps).

In the network transmission architecture, line coding is an important technology in the physical layer (PHY) of the wired Ethernet network and the data link layer. The original data is encoded by the line. It is transmitted through the cable. In addition, the line code can also be designed for the characteristics of the transmission medium, which is very important for the network transmission quality.

In response to the communication needs of wired networks, the present disclosure provides communication systems and methods for improving line coding. One aspect of the disclosure is a communication system including a packet stream conversion unit, a mapping unit, and Transmission unit. The packet stream conversion unit is configured to receive the four-bit packet stream and convert the four-bit packet stream into a six-bit packet stream. The mapping unit is configured to map the six-bit packet stream to the plurality of ternary bit streams, and map the idle symbols to the ternary bits according to at least one specific bit of the IDLE symbols in the six-bit packet stream. flow. The transmission unit is configured to transmit the stream of the ternary bit through a cable to the remote communication device.

One aspect of the disclosure is a communication method, comprising the steps of: converting a four-bit packet stream into a six-bit packet stream; mapping the six-bit packet stream to a plurality of ternary bit streams, and according to six At least one specific bit of at least one idle symbol in the bit stream stream, mapping the idle symbol to the ternary bit stream; transmitting the ternary bit stream to a remote communication device through a cable.

The above communication system and communication method can improve the baseline wander phenomenon of the receiver, reduce the error rate of the wired network communication, and improve the transmission efficiency.

100‧‧‧Communication system

110‧‧‧ Packet Flow Conversion Unit

112‧‧‧ bit-value conversion unit

114‧‧‧Data scrambler

116‧‧‧Side flow disrupter

120‧‧‧ mapping unit

130‧‧‧Transportation unit

200‧‧‧Communication method

1162‧‧‧Timer

1164‧‧‧Adder

S210~S240‧‧‧Steps

1A is a block diagram showing a communication system according to an embodiment of the present disclosure; FIG. 1B is a block diagram showing a side stream scrambler according to an embodiment of the present disclosure; and FIG. 2 is a block diagram according to an embodiment of the present disclosure. A flow chart showing a communication method.

FIG. 1A is a block diagram showing a communication system according to an embodiment of the disclosure. The communication system 100 mainly includes a part of a physical layer (PHY) in an open system interconnection reference model, and the physical layer is received by a medium access control part in a data link layer. Media independent interface data, and line encoding the line code to generate the line code and transmit the generated line code to the remote communication device through the cable (not shown in In the picture). In order to improve the correct rate of the line code of the remote communication device, a plurality of consecutive identical logic levels should be avoided in the generated line code, so as to prevent the remote communication device from misinterpreting the bit length of the line code. The components and functions of the components included in the communication system 100 will be described in detail below.

The communication system 100 includes a packet stream conversion unit 110, a mapping unit 120, and a transmission unit 130. The packet stream conversion unit 110 is configured to receive the four-bit packet stream and convert the four-bit packet stream into a six-bit packet stream. The mapping unit 120 is configured to map the six-bit packet stream to the plurality of ternary bit streams, and map the idle symbols to the ternary bits according to at least one specific bit of the IDLE symbols in the six-bit packet stream. Yuan stream. The transmission unit 130 is configured to transmit the ternary bit stream to the remote communication device through a cable. The packet stream conversion unit 110, the mapping unit 120, and the transmission unit 130 include appropriate logic, circuitry, and/or coding to implement the functions described above. In some embodiments, the above-described ternary bit contains three bit symbols of -1, 0, 1, and the like.

When the mapping unit 120 of the present disclosure maps a six-bit packet stream to a ternary bit stream, the number of combinations of possible ternary bits in the plurality of ternary bit streams is larger than that in the hexadecimal packet stream. The number of possible binary combinations of all the binary bits in the six bits is three or more. Therefore, when the mapping unit 120 maps the idle symbols of the six-bit packet stream to the ternary bit stream, the three mapped to the idle symbol are The combination of binary bit values has more flexibility, and it is possible to use a combination of ternary values that reduce the number of consecutive non-zero logical levels in a ternary bit stream. That is, the communication system 100 can reduce the baseline wander phenomenon, further improving the success rate of the remote communication device to interpret the line code, and achieving better communication quality.

The packet stream conversion unit 110 includes a bit number conversion unit 112, a data scrambler 114, and a side stream scrambler 116. The bit number conversion unit 112 includes appropriate logic, circuitry, and/or code for receiving the four-bit packet stream MII[3:0] from the media independent interface (not shown in FIG. 1A) and transferring it. It is a six-bit data stream 6b_stream[5:0].

In one embodiment, the bit number conversion unit 112 converts the four-bit packet stream MII[3:0] directly into a six-bit data stream 6b_stream[5:0] in a padding manner. In another embodiment, the bit number conversion unit 112 in the packet stream conversion unit 110 converts the four-bit packet stream MII[3:0] into a three-bit packet stream (4b3b), and then in a first-in-first-out manner. The three-bit packet stream is converted to a six-bit data stream 6b_stream[5:0].

The data shuffler 114 and the side stream shuffler 116 include appropriate logic, circuitry, and/or code to scramble the number of zeros and ones in the binary six-bit data stream 6b_stream[5:0], causing the scrambling The number of zeros and ones in the six-bit victim data stream Sd _n [5:0] is almost the same, so that the signal is random, and the speed of the clock frequency in the received signal is accelerated by the remote communication device at the receiving end. Data scrambler 114 and the side stream scrambler 116 scrambling a data stream six yuan 6b_stream [5: 0], the side stream scrambler 116 uses scrambler polynomial (scrambler polynomial) to generate a scramble value Scr _n-side [5: 0] The higher the number of scrambler polynomials, the higher the degree of randomness in the disturbed six-bit victim data stream Sd _n [5:0].

In one embodiment, the scrambler polynomial used by the sidestream scrambler 116 is g _M (x) = 1 + x ¹³ + x ³³ . In another embodiment, the scrambler polynomial used by the side stream scrambler 116 is g _S (x) = 1 + x ²⁰ + x ³³ . 1B is a block diagram of a sidestream scrambler 116 in accordance with an embodiment of the present disclosure, wherein the side stream scrambler 116 includes a delay 1162 and an adder 1164, and the upper half of the 1B is used for the scrambler polynomial g _M (x) = 1 + x ¹³ + x ³³ produces the side scrambling value Scr _n [5:0], and the lower half of the 1B graph is used to generate according to the scrambler polynomial g _S (x) = 1 + x ²⁰ + x ³³ side scrambling values Scr _n [5: 0].

The data shuffler 114 receives the side-scrambling value Scr _n [5:0] from the side stream scrambler 116 and the six-bit data stream 6b_stream[5:0] and processes it to generate a six-bit victim data stream Sd. _n [5:0]. The data shuffler 114 first generates the first subject using the equation g(x)=x ³ ^x ⁸ and Scr _n [0] and Scr _(n-1) [0] in the side scrambling value Scr _n [5:0]. The intermediate value stream Sy _n [2:0] is calculated as follows: Sy _n [0]=Scr _n [0]

Sy _n [1]=g(Scr _n [0])=Scr _n [3]^Scr _n [8]

Sy _n [2]=g ² (Scr _n [o])=Scr _n [6]^Scr _n [16]

By replacing all subscripts n of the above three equations with (n-1), Sy _(n-1) [2:0] can be obtained.

After generating the first disturbed intermediate value stream Sy _n [2:0], the data scrambler 114 utilizes the first disturbed intermediate value stream Sy _n [2:0] and the transmission mode signal tx_mode received by the data shuffler 114. The second disturbed intermediate value stream Sc _n [5:0] is determined, and the equation is as follows:

After generating the second disturbed intermediate value stream Scn[5:0], the data scrambler 114 uses the second disturbed intermediate value stream Sc _n [5:0] and the data enable signal tx_enable received by the data shuffler 114. And the local receiver state loc_rcvr_status determines the six-bit victim data stream Sd _n [5:0], as shown below:

The above six-bit data stream 6b_stream[5:0], the second victim intermediate value stream Sc _n [5:0], and the six-bit victim data stream Sd _n [5:0] all have 6 binary bits. The yuan is a unit, so they all belong to the six-bit packet stream. In addition, the six-bit data stream 6b_stream[5:0], the second disturbed intermediate value stream Sc _n [5:0], the six-bit victim data stream Sd _n [5:0], and the transmission enable signal tx_enable For the timing signal, the latest signal is represented by n, and the number in parentheses (such as n-6, n-1) represents the time difference from the latest signal.

The packet stream conversion unit 110 outputs the scrambled and randomized six-bit victim data stream Sd _n [5:0], and the mapping unit 120 in the communication system 100 receives the six-bit victim data stream Sd _n [5:0] And the six-bit victim data stream Sd _n [5:0] includes at least one IDLE symbol, each idle symbol contains 6 binary bits, and the mapping unit 120 pairs the six-bit victim data stream Sd _n [5:0] for further processing, mapping it to a plurality of ternary bit streams to transmit the six-bit victim data stream Sd _n [5:0] to the remote communication device via the cable.

In an embodiment, the mapping unit 120 maps the data symbols in the six-bit victim data stream Sd _n [5:0] to the four ternary bit streams (6B4T), and the comparison table is as shown in Table 1. .

When mapping the idle symbol to the ternary bit stream, the mapping unit 120 determines the ternary value mapped to the ternary bit stream according to the specific bit of the idle symbol. In an embodiment, the mapping unit 120 maps the idle symbol to the ternary bit stream according to a specific bit, including a least significant bit, that is, the mapping unit 120 is based on the least significant bit of the least significant bit. The value determines the triple value of the first bit stream T1 in the ternary bit stream.

Specifically, in another embodiment, in the least significant bit When it is zero, the mapping unit 120 determines that the third bit value of the first bit stream T1 is zero, and when the least significant bit is non-zero, the mapping unit determines that the third bit value of the first bit stream T1 is non-zero (1 or -1). Through the above coding rule, the efficiency and the correct rate of the clock in the received line code of the remote communication device at the receiving end will increase.

In a further embodiment, the mapping unit 120 maps the idle symbol to the ternary bit stream according to the specific bit element including the first intermediate bit and the most significant bit, and the mapping unit 120 is configured to use A binary value of the intermediate bit and the most significant bit determines a ternary value of the second bit stream T2 in the ternary bit stream. Specifically, the mapping unit 120 uses the hexadecimal victim stream Sd Sd _n [3] in _n [5:0] is used as the first intermediate bit. When the first intermediate bit and the most significant bit are simultaneously zero, the third bit value of the second bit stream T2 is zero, otherwise The third bit value of the second bit stream T2 is non-zero.

In still another embodiment, the mapping unit 120 maps the idle symbol to the ternary bit stream according to the specific bit element including the first intermediate bit and the second intermediate bit, and the mapping unit 120 is configured to use the first intermediate bit according to the first intermediate bit. The binary value of the second intermediate bit and the second intermediate bit determine the triple value of the third bit stream T3 in the ternary bit stream. Specifically, the mapping unit 120 uses the six-bit victim data stream Sd _n [ Sd _n [3] in 5:0] as the first intermediate bit, and uses Sd _n [4] in the six-bit victim data stream Sd _n [5:0] as the second intermediate bit, when the first When an intermediate bit and a second intermediate bit are simultaneously 1, the third bit value of the third bit stream T3 is zero, otherwise the third bit value of the third bit stream T3 is non-zero.

In a particular embodiment, mapping unit 120 incorporates the above There are encoding rules to map the IDLE symbol in the binary six-bit packet stream to four ternary bit streams (6B4T), as shown in Table 2.

In Table 1 and Table 2, the numbers of the first bit stream T1 to the fourth bit stream T4 are used to distinguish different three-dimensional bits, and are not used to limit the order. In Tables 1 and 2, the fields T1~T4 can be exchanged.

The traditional line coding mostly converts the four-bit packet received from the media independent interface into a three-bit packet stream, and directly maps the three-bit packet stream to Two ternary bit streams, but all the values of the two ternary bits may be combined (3 to the power of 2) only the combined number of all the values of the three binary bits in the tributary stream (2 to the power of 3) one more, so that the choice of the value combination of the ternary bit in the mapping is limited, so that the traditional line coding circuit wants to add symbols in the ternary bit stream (such as delimitation for labeling) When there is not enough value combination, there are consecutive multiple non-zero ternary values in the generated ternary bit stream, which leads to severe baseline drift.

On the other hand, from the above comparison table 1 and table 2, when the binary hexadecimal packet is streamed into four ternary bit streams, the number of all possible hexadecimal binary values is 64 (2). 6th power), and the number of all possible quaternion ternary values is 81 (3 to the 4th power), so there are still 17 ternary digit combinations, but {0,0 , 0,0}, {1,1,1,1} and {-1,-1,-1,-1} have four consecutive ternary values, which causes the problem of baseline drift, so The mapping unit 120 is not used, and after the above combination is eliminated, the remaining 14 combinations are used for delimiters placed between different packets. The delimiter can be a start stream delimiter (SSD), an end stream delimiter (ESD), or an error end stream delimiter (ERR_ESD). The first one is used to indicate The beginning of the packet, the second is used to indicate the end of the packet, and the third is used to indicate the end of the packet and to indicate the occurrence of an abnormal condition.

In an embodiment, the mapping unit 120 adds a delimiter to the ternary bit stream, and the consecutive three non-zero triad values included in the delimiter are not It is identical, that is, the delimiter does not contain three consecutive non-zero triad values. Therefore, according to the contents of Table 2, all the four-bit triple-digit value combinations are deducted from the combination already used for mapping the idle symbols, and then deducted from the combination of three consecutive value values of the same three-digit value, where {0, 1, 1, 1 } and {-1, 1, 1, 1} each have three consecutive 1's or -1s, and the mapping unit 120 does not use the above combination as a delimiter. In particular, in some of these embodiments, mapping unit 120 uses consecutive {1, 1, 0, 0}, {1, 1, 0, 0} as the starting delimiter, and uses consecutive {-1 , -1,0,0}, {-1,-1,0,0} as the end delimiter, in addition to using consecutive {1,-1,0,0}, {1,-1,0,0 } End the delimiter as an error. In this way, the problem of the baseline drift of the remote communication device at the receiving end can be avoided, and the transmitted line code can be successfully interpreted.

In still another embodiment, the transmission unit 130 receives the encoded ternary bit stream T[3:0] from the mapping unit 120 (representing a ternary bit stream composed of T1, T2, T3, and T4) The ternary bit stream T[3:0] is transmitted to the remote communication device via the cable in a PAM-3 encoding manner. In one embodiment, the cable is a pair of twisted pairs, and the transmission unit 130 divides the ternary bit stream T[3:0] according to {T1, T2, T3, T4} or {T4, T3, T2, The order of T1} is transmitted through the twisted pair to the remote communication device. In another embodiment, the cable is a 4-pair twisted pair, and the transmission unit 130 transmits one of the ternary bit streams T[3:0] through each twisted pair.

By first streaming the four-bit packet to a six-bit packet stream and then converting the six-bit packet to a ternary bit stream, the communication system 100 maps the six-bit packet stream to the ternary bit stream. It has higher flexibility, so it can avoid the continuous same bit value in the transmitted line code, which greatly improves the benchmark. The phenomenon of line drifting further enhances the success rate of the remote communication device to interpret the line code. In addition, the mapping unit 120 in the communication system 100 further transmits the transmission line by using the coding rule to enable the remote communication device at the receiving end to quickly and efficiently obtain the transmission line. The clock information in the code further achieves better communication quality. The experimental data also shows that in terms of the power spectral density of the transmitted data, the technical solution of the present disclosure performs better than the conventional conversion of the three-bit binary to the binary ternary.

FIG. 2 is a flow chart of a communication method according to an embodiment of the disclosure. Although the communication method 200 is described in the flowchart in a particular order, the order of the steps referred to in the present invention is not limited. For the sake of convenience and clarity, the communication system 100 shown in FIG. 1A is described as an example, but is not limited thereto.

First, the communication system 100 receives a four-bit packet stream from the media independent interface and converts the four-bit packet stream into a six-bit packet stream (step S210).

The communication system 100 maps the obtained six-bit packet stream to a plurality of ternary bit streams, and maps the idle symbols to the ternary bit stream according to at least one specific bit in at least one of the six-bit packet streams. (Step S220). In an embodiment, the specific bit used by the communication system 100 for mapping includes the least significant bit, and the communication system 100 determines a first bit stream in the ternary bit stream according to the least significant bit in the idle symbol. The triple value. Specifically, when the least significant bit is zero, the communication system 100 determines that the third bit value of the first bit stream is zero, and when the least significant bit is non-zero, the communication system 100 determines the third bit stream. The carry value is non-zero.

In other embodiments, the specific bit used by the communication system 100 for mapping includes the first intermediate bit and the most significant bit, and the communication system 100 determines the three-in-one according to the first intermediate bit and the most significant bit in the idle symbol. The triple value of a second bit stream in the bit stream. In other embodiments, the particular bit used by the communication system 100 to map includes a first intermediate bit and a second intermediate bit, and the communication system 100 is based on the first intermediate bit and the second intermediate bit in the idle symbol. Determines the triple value of a third bit stream in the ternary bit stream.

By using the communication method 200, the communication system 100 maps the data symbols and the idle symbols in the six-bit packet stream to the ternary bit stream, and in one embodiment, the number of ternary bit streams is four. , the number of quaternion ternary value combinations (3 to the power of 4) is higher than the number of hexadecimal binary values combined (2 to the 6th power), increasing the mapping to the quaternion ternary value selection, providing a map of six The bit stream flows to the elasticity of the ternary bit stream.

The communication system 100 adds a delimiter to the ternary bit stream (step S230), and selects the remaining ternary bit value combination to include three identical consecutive non-zero ternary values, that is, the communication system 100 Any three consecutive non-zero triad values of the delimiter added will not be identical. In this way, the performance of the baseline drift can be improved, and the data transmission accuracy rate can be improved.

After the communication system 100 maps the six-bit packet stream to the ternary bit stream, the ternary bit stream is transmitted to the remote communication device via the cable (step S240). In one embodiment, communication system 100 transmits a ternary bit stream using PAM-3 encoding.

The implementation details of the above steps are as described above, and are no longer here. Said.

The communication system and communication method described in the present disclosure can improve the baseline drift phenomenon experienced by the remote communication device at the receiving end. In addition, the encoding rules described in the present disclosure include converting the six-bit packet stream into at least four three-inputs. The bit stream and the ternary value of the ternary bit stream are determined according to the specific bit of the hexadecimal packet stream. After the above coding rule, the remote communication device can efficiently lock the clock information in the line code. And correctly interpret the line code, so that the error rate of wired network communication is reduced, and the transmission efficiency is improved.

100‧‧‧Communication system

110‧‧‧ Packet Flow Conversion Unit

112‧‧‧ bit-value conversion unit

114‧‧‧Data scrambler

116‧‧‧Side flow disrupter

120‧‧‧ mapping unit

130‧‧‧Transportation unit

Claims (10)

A communication system includes: a packet stream conversion unit configured to receive a four-bit packet stream and convert the four-bit packet stream into a six-bit packet stream; and a mapping unit to stream the six-bit packet Mapping to a plurality of ternary bit streams, and mapping the at least one idle symbol to the ternary bits according to at least one specific bit in at least one IDLE symbols in the six-bit packet stream And a transmission unit for transmitting the ternary bit streams to a remote communication device through a cable. The communication system of claim 1, wherein the at least one specific bit comprises a least significant bit, and the mapping unit is configured to determine the ternary bit stream according to the binary value of the least significant bit A three-bit value of the first bit stream. The communication system of claim 1, wherein the at least one specific bit comprises a first intermediate bit and a most significant bit, and the mapping unit is configured to use the first intermediate bit and the most significant bit The binary value determines the triple value of one of the second bit streams in the ternary bit stream. The communication system of claim 1, wherein the at least one specific bit comprises a first intermediate bit and a second intermediate bit, the mapping unit configured to use the first intermediate bit and the second intermediate bit The binary carry value determines the triple value of one of the third bit streams in the ternary bit stream. The communication system of claim 1, wherein the mapping unit adds at least a delimiter to the ternary bit streams, and the consecutive three non-zero ternary values of the at least one delimiter are not identical. A communication method includes: converting a four-bit packet stream into a six-bit packet stream; mapping the six-bit packet stream to a plurality of ternary bit streams, and according to at least one of the six-bit packet streams At least one specific bit in the IDLE symbols, mapping the at least one idle symbol to the ternary bit streams; and transmitting the ternary bit streams to a remote communication through a cable Device. The communication method of claim 6, wherein the step of mapping the at least one idle symbol to the ternary bit stream according to the at least one specific bit comprises: determining the value according to a binary value of a least significant bit A triple value of a first bit stream in the ternary bit stream, wherein the at least one specific bit bit comprises the least significant bit. The communication method of claim 6, wherein the mapping the at least one idle symbol to the ternary bit stream according to the at least one specific bit comprises: according to a first intermediate bit and a most significant bit The binary value determines a triple value of the second bit stream of the ternary bit stream, wherein the at least one specific bit includes the first intermediate bit and the most significant bit. The communication method of claim 6, wherein the mapping the at least one idle symbol to the ternary bit stream according to the at least one specific bit comprises: according to a first intermediate bit and a second middle bit The binary value of the yuan, Determining a triplet value of one of the third bitstreams of the ternary bitstream, wherein the at least one particular bit comprises the first intermediate bit and the second intermediate bit. The communication method according to Item 6, further comprising: adding at least a certain delimiter to the ternary bit stream, and the consecutive three non-zero triad values in the at least one delimiter are not completely the same.