KR100705924B1 - Method for assigning code and producing code-pair by selecting QLS - Google Patents

Abstract

The present invention relates to orthogonal spreading for use in CDMA (Code Division Multiple Access) mobile communication. In particular, a peak-to-average power ratio is generated by generating a code pair according to a QSI (Quasi-LS: Quasi-Large Synchronization) code selection. PAPR: Reduces Peak-to-Average Power Ratio and assigns QLS codes sequentially to increase the length of the effective interference free window (EIFW) or to improve the cross-correlation characteristics. The present invention relates to a code pair generation and code assignment method.

Accordingly, the present invention proposes a method of improving the peak-to-average power ratio by sequentially suggesting a code pair that minimizes the 180 degree phase shift between the codes assigned to the I and Q components, and proposes a method of sequentially assigning the QLS codes. There is an effect to increase the length of the effective interference cancellation window.

Code Assignment, Effective Orthogonal Code Set, Effective Interference Cancellation Window, Peak to Average Power Ratio

Description

Method for assigning code and producing code-pair by selecting QLS}

1 is a BPSK (Binary Phase Shift Keying) spreading scheme using a QLS code

2 is a diagram illustrating a quadrature phase shift keying (QPSK) spreading scheme using a QLS code.

3 is a complex diffusion method of complex diffusion using a QLS code

4 is a flowchart for classifying a QLS code into a set of representative valid orthogonal codes.

5 is a flowchart for selecting a method for allocating a QLS code of a representative valid orthogonal code set.

The present invention relates to orthogonal spreading for use in CDMA (Code Division Multiple Access) mobile communication. In particular, a peak-to-average power ratio is generated by generating a code pair according to a QSI (Quasi-LS: Quasi-Large Synchronization) code selection. PAPR: Reduces Peak-to-Average Power Ratio and assigns QLS codes sequentially to increase the length of the effective interference free window (EIFW) or to improve the cross-correlation characteristics. The present invention relates to a code pair generation and code assignment method.

More specifically, the present invention relates to a quadrature phase shift keying (QPSK) diffusion method in which different diffusion codes are assigned to I (Inphase) components, which are in-phase components, and Q (Quadrature) components, which are quadrature components, respectively. In order to reduce peak-to-average power ratio (PAPR) by selecting an optimal code pair for the complex diffusion scheme (Fig. 3). In addition, when allocating spreading codes in the QPSK spreading scheme and the complex spreading scheme, the sequential allocation method of spreading codes is improved to increase the length of the effective interference elimination window (EIFW) or to improve the cross-correlation characteristics.

In addition, even in the case of using the BPSK (Binary Phase Shift Keying) spreading scheme (Fig. 1) which allocates the same spreading code to the I and Q components, the length of the effective interference cancellation window (EIFW) is increased by sequentially assigning the QLS codes. Or to improve cross-correlation properties.

In general, the basic concept of the spread spectrum technology used by the CDMA method is to spread the signal transmitted through the encoding process over a wideband, and then to despread it through the decoding process to the narrowband to detect a desired signal. At this time, through spreading and despreading, the desired signal is restored to the original narrowband signal having a high power, but other user's signals act like a low power broadband noise signal.

The characteristics of autocorrelation and crosscorrelation required for the diffusion code used in this diffusion and despreading process are as follows. In order to detect the desired signal, autocorrelation should have a maximum value when there is no time offset and a small value at other time differences. Also, in order to be distinguished from spreading codes used by other users, small cross-correlation values are used at all time differences.

In order to satisfy the above autocorrelation and cross-correlation characteristics, the conventional CDMA method uses PN (Pseudo Noise) code and Walsh code together as a spreading code. The PN code above satisfies the required characteristic in autocorrelation, and the Walsh code satisfies the required characteristic in cross-correlation.

In the cross-correlation requirement, there is no interference between spreading codes assigned to different users in the case of one channel path, but in the case of multiple channel paths, there is interference between spreading codes. More specifically as follows.

In the case of one channel path, the amount of mutual interference between spreading codes is determined only by the correlation value when there is no time difference. On the other hand, in the case of multiple channel paths, the amount of mutual interference between the spreading codes is influenced not only by the cross-correlation value when there is no time difference but also by the cross-correlation value of the path delay times between the channel paths. Will receive.

Therefore, in a multipath channel environment having a plurality of channel paths, which are generally referred to as actual channel environments, not only when the cross-correlation characteristics of the spreading codes have no time difference but also the cross-correlation values at different time differences are important. .                         

After all, ideally, the cross-correlation of spreading code should have a value of zero for every time difference. However, a code that satisfies both the above-described cross-correlation characteristics and the required characteristics of the above-described autocorrelation at one time is not known at present.

That is, looking at the PN code and Walsh code used in the conventional CDMA method, the PN code satisfies the requirements of autocorrelation but does not satisfy the requirements of cross-correlation. In addition, Walsh code does not satisfy the requirements of autocorrelation and only partially meets the requirements of cross-correlation.

In other words, when the cross-correlation property of Walsh code is examined, the cross-correlation value when there is no time difference has 0, but the cross-correlation value when the time difference is not 0 has a nonzero value.

On the other hand, the LS code completely satisfies the autocorrelation and cross-correlation required characteristics in a certain time interval.

A time difference section in which the autocorrelation and cross-correlation characteristics are perfect is defined as an interference free window (IFW).

Looking at the autocorrelation characteristics in the interference cancellation window, when there is no time difference, the autocorrelation value is the maximum value, and the autocorrelation value is 0 even when the time difference is any time difference in the non-interference removal window.

That is, when the time difference is limited to only the interval of the interference cancellation window, the autocorrelation value when the time difference is zero has a maximum value, and when the time difference is not zero, the autocorrelation value becomes zero.

In addition, the cross-correlation property of the LS code has a cross-correlation value of 0 even when the time difference is any time difference in the interference cancellation window.

As a result, in a multi-channel path environment, if the path delay time between each channel path exists in the interference cancellation window, interference between spreading codes assigned to each user can be eliminated. Therefore, the interval of time difference satisfying the autocorrelation and cross-correlation characteristics as described above is called an interference cancellation window IFW.

Conventionally, the PN code and the Walsh code are used together to partially satisfy the autocorrelation and cross-correlation requirements, while the LS code uses only the LS code to completely characterize the auto-correlation and cross-correlation requirements at time differences in the interference cancellation window. You will be satisfied.

However, while the LS code has good autocorrelation and cross-correlation characteristics in the time difference in the interference cancellation window, there is a disadvantage in that the number of codes actually available is small.

If the set of LS codes satisfying the above autocorrelation and cross-correlation characteristics is an orthogonal code set, an inverse relationship is established between the length of the IFW section and the number of elements in the orthogonal code set. Therefore, while the amount of interference components is greatly reduced due to the generation of the interference cancellation window as described above, the number of available orthogonal codes is limited, thereby limiting the increase in channel capacity.

In order to solve the above problems, a new spreading code, QLS code, which increases the length of the interference cancellation window and the number of elements in the orthogonal code set, has been proposed.

The QLS code increases the number of elements of an effective orthogonal code set and increases an effective interference free window compared to the LS code.                         

의 구간동안 단지 시간차=+1,-1일 때 오직 한 쌍의 부호들간에서만 상호상관값이 0이 되지 않고, 간섭제거창

의 구간 중 시간차=+1,-1이 아닌 나머지 시간차 동안에는 직교성을 만족시킬 때, 상기의 특성을 만족하는 직교 부호들의 집합을 유효 직교부호 집합이라 정의하고, 상기의 특성을 만족하는 간섭제거창을 유효 간섭제거창(EIFW)이라 정의한다.In the above, the time difference which is the interference cancellation window section

When the time difference is equal to + 1, -1, the cross-correlation value does not become zero only for a pair of codes, and the interference cancellation window

When the orthogonality is satisfied during the remaining time difference other than the time difference = + 1, -1, the orthogonal codes satisfying the above characteristics are defined as the effective orthogonal code sets, and the interference elimination window satisfying the above characteristics is defined. This is defined as an effective interference cancellation window (EIFW).

In addition, in the spreading method using the QLS code, a BPSK spreading method (FIG. 1) in which the same QLS code is used for the I component and the Q component, and a method for assigning different QLS codes to the I component and the Q component, respectively. QPSK diffusion method (FIG. 2) which spreads by using, and a complex diffusion method (FIG. 3) to reduce power imbalance between I component and Q component is proposed.

However, when different QLS codes are assigned to the I component and the Q component to spread, the diffusion code of the I component and the Q component of the Q component can be changed at the same time, and thus the phase shift of the spread signal may be 180 ⁰ . . This 180 degree phase shift adversely affects the envelope deviation of the signal after the spread signal passes through the filter. That is, the peak-to-average power ratio value is increased.

Therefore, in order to solve the above problems, a method of allocating a QLS code by selecting an orthogonal code set that satisfies autocorrelation and cross-correlation characteristics, and classifying it into a code pair set and a code set of the orthogonal code set The proposed method improves the peak-to-average power ratio by minimizing the 180 degree phase shift between the codes assigned to the I and Q components. In addition, by improving the method of assigning codes in orthogonal code sets, the effective interference cancellation window is temporarily increased.

In the case of a spreading scheme in which the same code is assigned to the I and Q components, the effective interference elimination window is temporarily increased by improving the method of allocating codes in the orthogonal code set.

Code pair generation and code allocation method according to the selection of the QLS code of the present invention,

의 QLS부호의 관계식이 다음과 같이 표시되는 경우에 있어서,Code length

In the case where the relational expression of the QLS code of

Among the QLS codes, a set of codes that are orthogonally orthogonal to each other during the interference cancellation window period is generated.

라 하고, 집합의 원소를

으로 표시했을 때, 유효직교부호 집합으로

를 선택시

가 되고 원소들은

의 관계식이 성립하게 되는 것을 특징으로 한다.A set representing a set of effective orthogonal codes.

And the elements of the set

When expressed as a set of orthogonal codes

When selecting

And the elements

It is characterized by the fact that the relation of.

의 집합을

로 표현하고, I성분 부호와 Q성분 부호간 최소 180도 위상천이가 일어나도록 하는 부호쌍을 The present invention also provides a set of selected effective orthogonal codes.

Set of

And a code pair for causing a phase shift of at least 180 degrees between the I component code and the Q component code.

(I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)

와 같이 표현하는 것을 특징으로 한다.

It is characterized by the expression as.

로 분류하고,In addition, the present invention, the code pair between the I component code and the Q component code in consideration of the peak-to-average power ratio in the optimal code pair set of the following code pair (code pair)

Classified as

라고 할 때, 부호쌍집합은 다음과 같이 정의되고,Set of effective orthogonal codes

In this case, the sign pair set is defined as follows.

(Code_left, Code_right)=(I_branch부호,Q_branch부호) 또는 (Q_branch부호,I_branch부호)} (단,Q=

)P = {(Code _left , Code _right )

(Code _left , Code _right ) = (I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)} (Q =

)

The actual code pair set is

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의하고,Denotes a set of generalized code pairs above

Is

end

Can only be displayed when

If

Is an initial set, defined separately as above,

After selecting the code pair set in order from the defined code pair sets, the code pair is assigned to the I component and the Q component in each code pair set.

와

로 나누고, In addition, the present invention, two types of code pairs in order to obtain the effect of improving the cross-correlation characteristics of the QLS code

Wow

Divide by

이라 할 때 부호쌍 집합은 다음과 같이 정의되고,Set of orthogonal codes

Suppose that the set of sign pairs is defined as

또는

= {(Code_left , Code_right)

(Code_left, Code_right)=(I_branch부호,Q_branch부호) 또는 (Q_branch부호,I_branch부호)}

or

= {(Code _left , Code _right )

(Code _left , Code _right ) = (I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)}

In this case, the actual code pair set is

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉,

은 초기집합으로서 위와 같이 별도로 정의되고, 또한 일반화된 부호쌍 집합표시 는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의하고,Denotes the generalized code pair set above.

Is

end

Can only be displayed when

In other words,

Is an initial set, defined separately as above, and also a generalized set of code pairs. Is

end

Can only be displayed when

If

Is an initial set, defined separately as above,

들에서 모든 부호쌍을 I성분과 Q성분에 할당한 다음 부호쌍집합

들에서 부호쌍을 I성분과 Q성분에 할당하거나, 순서를 바꾸어 부호쌍 집합

들에서 모든 부호쌍을 I성분과 Q성분에 할당한 다음 부호쌍집합

들에서 부호쌍을 I성분과 Q성분에 할당하는 것을 특징으로 한다.A code pair set once from the code pair sets defined above

Assign all sign pairs to the I and Q components

Code pairs are assigned to I and Q components, or the order is changed

Assign all sign pairs to the I and Q components

Is assigned to the I component and the Q component.

와

로 나누고, In addition, the present invention, two sets of code sets in order to obtain the effect of improving the cross-correlation characteristics of the QLS code

Wow

Divide by

이라 할 때 부호 집합

와

는 다음과 같이Set of orthogonal codes

The set of symbols

Wow

As follows

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의되고, 또한 일반화된 부호집합표시

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의하고,Defined code set representation as defined above

Is

end

Can only be displayed when

If

Is an initial set, defined separately as above, and also a generalized code set representation.

Is

end

Can only be displayed when

If

Is an initial set, defined separately as above,

들에서 모든 부호를 I성분과 Q성분에 같은 부호로 할당한 다음 부호집합

들에서 부호를 I성분과 Q성분에 같은 부호로 할당하거나, 순서를 바꾸어 부호집합

들에서 모든 부호를 I성분과 Q성분에 같은 부호로 할당한 다음 부호집합

들에서 부호를 I성분과 Q성분에 같은 부호로 할당하는 것을 특징으로 한다.A code set once in the defined code pair sets

Assigns all the signs in the I and Q components to the same sign and then

Assigns the same sign to the I and Q components, or reverses the order

Assigns all the signs in the I and Q components to the same sign and then

Are assigned to the same component as the I component and the Q component.

In addition, the present invention comprises the steps of: generating an effective orthogonal code set in assigning a QLS code; Selecting a representative valid orthogonal code from the set of effective orthogonal codes; Determining whether different QLS codes are assigned to the I component and the Q component; Selecting a code pair combination that minimizes the peak-to-average power ratio; It is characterized by sequentially assigning the QLS codes by determining whether N / 2 or less of the total codes N are used.

In addition, the present invention comprises the steps of: generating an effective orthogonal code set in assigning a QLS code; Selecting a representative valid orthogonal code from the set of effective orthogonal codes; Determining whether different QLS codes are assigned to the I component and the Q component; According to the result of the determination, the code set is classified based on the interference elimination window, and it is determined whether to use N / 2 or less out of N codes, and apply the sequential allocation method (3) or (4) of the QLS code of the present invention. It features.

With reference to the accompanying drawings will be described a code pair generation and code allocation method according to the selection of the QLS code of the present invention.

First, when the effective orthogonal code set is defined, a set of QLS codes that satisfy autocorrelation and cross-correlation characteristics in a desired effective interference cancellation window (EIFW) is defined as an effective orthogonal code set.

의 구간동안 단지 시간차=+1,-1일 때 오직 한 쌍의 부호들간에서만 상호상관값이 0이 되지 않고, 시간차

의 구간 중 +1,-1이 아닌 나머지 시간차 동안에는 상호상관값이 0이 되며, 또한 자기상관특성은 시간차

의 구간동안 시간차가 없을 때는 최대값을 갖고, 단지 시간차=+1,-1일 때만 최대값의 절반값을 가지며, 그 외의 나머지 시간차에서는 0의 값 을 갖는다. 상기와 같은 시간차구간을 유효 간섭제거창이라고 하며, 간섭제거창과의 차이점은 시간차=+1,-1일 때 상호상관과 자기상관값이 0이 되지 않는 다는 점뿐이다. In the above description, the effective interference cancellation window section refers to a time difference section satisfying the following characteristics. That is, time difference

When the time difference is only + 1, -1 for the interval of, the cross-correlation value does not become zero only for a pair of codes.

During the remaining time difference that is not + 1, -1, the cross-correlation value becomes 0, and the autocorrelation property is time difference.

The maximum value is obtained when there is no time difference during the interval, and only half of the maximum value is obtained when the time difference is equal to + 1, -1. Such a time difference section is called an effective interference cancellation window, and the only difference from the interference removal window is that the cross-correlation and auto-correlation values do not become zero when the time difference is + 1, -1.

의 QLS부호의 유효간섭제거창

의 구간동안 서로 유효 직교관계가 성립하는 QLS부호의 개수는,

일 때,

이다.Thus, code length

Effective interference elimination window of QLS code

The number of QLS codes that have an effective orthogonal relationship with each other during

when,

to be.

는 자연수이고,

는

인 정수이며,

은

인 자연수이다.From above

Is a natural number,

Is

Is an integer

silver

It is a natural number that is.

As a result, the QLS code increases the number of elements of the effective orthogonal code set in terms of the effective interference cancellation window.

The code allocation method increases the length of the interference cancellation window or improves the cross-correlation value using the QLS code, and the peak power-to-average power ratio is reduced by minimizing the 180-degree phase shift between the codes assigned to the I and Q components. Code allocation methods for improvement are described.

First, the selection of orthogonal code sets for achieving the above purpose is described.                     

First, the relation for generating the QLS code is

을 이용하여

과

을 생성하고, 상기

을 이용하여

을 생성한다., Sign

Using

and

Create and remind

Using

Create

의 QLS부호는 다음과 같이 표시할 수 있다.Meanwhile, the code length

The QLS code of can be expressed as follows.

(단,

는

인 정수)는

번째 QLS부호를 나타내는

의 크기를 갖는 행 벡터이고,

은

의 크기를 갖고 값이 0인 영행렬(zero matrix)이고,

과

은

에서 사용되는

의 크기를 갖는 부분 행렬이다.From above

(only,

Is

Is an integer)

The first QLS code

Is a row vector with the size of

silver

Is a zero matrix of size 0 and

and

silver

Used in

It is a partial matrix with the size of.

개의 집합이 존재하며, 각 유효직교 집합내의 원소개수는

개이며, 상기 유효직교부호 집합(Effective Orthogonal code set)

들은 다음과 같이 표시할 수 있다.Of the above QLS codes, the set of effective orthogonal codes, which is a set of codes that are orthogonal to each other effectively during the interference cancellation window,

Sets exist, and the number of elements in each effective orthogonal set

Is an effective orthogonal code set

Can be expressed as:

을 사용하게되면, 나머지 유효직교부호 집합

들은 사용할 수가 없게 된다. 만일 여러 가지 유효직교부호 집합들을 동시에 사용하게되면 유효간섭제거창내에서 자기상관특성과 상호상관특성이 유지되지 않게 된다.Selecting any of the above set of effective orthogonal codes has the same characteristics. However, there is only one set of valid orthogonal codes that can be used in practice. That is, if the set of effective orthogonal codes

If you use, the remaining set of orthogonal codes

They cannot be used. If multiple sets of effective orthogonal codes are used at the same time, autocorrelation and cross-correlation characteristics are not maintained in the effective interference cancellation window.

라고 하고, 집합의 원소는

로 표시하도록 정의한다.Therefore, a set representing a set of effective orthogonal codes

The elements of the set

Define to display.

와 집합

의 원소들간의 대응관계는 원소 번호의 오름차순으로 일대일 대응관계가 된다. 즉 , 만약 유효직교부호 집합으로

을 선택하면

이 되고, 직교 집합내 원소들은

의 관계식을 갖게 된다. 따라서 만일 유효직교부호 집합으로

를 선택한다면,

가 되고 원소들은

의 관계식이 성립하게 된다.Each set of valid orthogonal codes

And set

The correspondences between the elements of are in a one-to-one correspondence in ascending order of element numbers. That is, if the set of orthogonal codes

If you select

And the elements in the orthogonal set

You have a relation of. Therefore, if the set of effective orthogonal codes

If you choose

And the elements

The relation of is established.

Secondly, a description will be given of an optimal code pair for selecting a combination of the minimum 180 degree phase shift when different codes are assigned to the I component and the Q component as shown in FIG.

As described above, the smaller the 180 degree phase shift between the I component spreading code and the Q component spreading code, the smaller the peak power-to-average power ratio (PAPR). That is, when the QLS code is used as the spreading code, each spreading code pair (I _branch code, Q _branch code) or (Q _branch code, I _branch code) must be selected from the orthogonal code set. Choosing a combination that minimizes the 180-degree phase shift between the I-component code and the Q-component code is the optimal code pair.

This section explains how to construct the optimal code pair.

라하고, 각 유효직교부호집합

의 구성요소를 일정한 QLS식으로 정의하고, 유효직교부호집합을 대표하는 집합을

라고 표현하여, 상기

의 집합의 원소를

로 표시했을 때, 유효직교부호집합

와 대표집합

의 원소들간의 대응관계는 원소번호의 오름차순으로 일대일 관계가 성립하므로, 만일 유효직교부호집합

를 선택시, 유효직교부호집합을 대표하는 집합을

라고 하면

관계식이 성립하게 되어, 유효직교부호집합은

으로 표현된다.The effective orthogonal code selection method described above, that is, the set of effective orthogonal codes generated by the QLS generation relation

D) each set of effective orthogonal codes;

Defines a component of the equation by a constant QLS expression, and represents a set representing a set of effective orthogonal codes.

Expressing,

Elements of a set of

When displayed as, orthogonal code set

And representative set

The correspondence relations between the elements of are in one-to-one relationship in ascending order of element number, so

, Select a set representing a set of effective orthogonal codes.

Say

The relational expression is established, and the effective orthogonal code set

It is expressed as

Therefore, a code pair for causing a phase shift of at least 180 degrees between the I component code and the Q component code can be expressed as follows.

(I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)

to be.

Third, the case of the spreading method of allocating different codes to the I component and the Q component as shown in FIG. 2 among the sequential allocation methods of the QLS code will be described.

** Sequential allocation method of QLS code (1)

로 분류(정의)하여, 부호쌍 집합

내에서 부호쌍을 할당하는 방식이다. This method is a sequential allocation method of QLS codes for minimizing peak-to-average power ratios. In the case of the spreading method for assigning different codes to I and Q components as shown in FIGS. Considering the peak-to-average power ratio in the optimal code pair, the code pair between the I component code and the Q component code of the optimal code pair proposed above is a set of code pairs as follows.

Set of code pairs

This is a method of allocating code pairs within a network.

라하고, 각 유효 직교부호집합

의 구성요소를 일정한 QLS식으로 정의하고, 유효 직교부호집합을 대표하는 집합을

라고 표현하여, 상기

의 집합의 원소를

으로 표시했을 때, 유효 직교부호집합

와 대표집합

의 원소들간의 대응관계는 원소번호의 오름차순으로 일대일 관계가 성립하므로, 만일 유효 직교부호집합

를 선택시, 유효 직교부호집합을 대표하는 집합을

라고 하면

관계식이 성립하게 되어, 유효 직교부호집합은

라 할 때, 부호쌍 집합을 다음과 같이 정의할 수 있다.The effective orthogonal code selection method described above, that is, each valid orthogonal code set generated by the QLS generation relation

D) each effective orthogonal code set;

Defines a component of the equation by a constant QLS expression, and represents a set representing an effective orthogonal code set.

Expressing,

Elements of a set of

Set of valid orthogonal codes

And representative set

The correspondence relations between the elements of are in a one-to-one relationship in ascending order of element numbers.

, Select a set representing a set of valid orthogonal codes.

Say

A relational expression is established, and the effective orthogonal code set

In this case, the code pair set may be defined as follows.

(Code_left, Code_right)=(I_branch부호,Q_branch부호) 또는 (Q_branch부호,I_branch부호)} (단,Q=

)
P = {(Code _left , Code _right )

(Code _left , Code _right ) = (I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)} (Q =

)

이라 할 때, 실제 부호쌍은Therefore, the set of effective orthogonal codes selected according to the effective orthogonal code selection method

In this case, the actual code pair

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의된다. Generalized code set representation

Is

end

Can only be displayed when

If

Is an initial set and is separately defined as above.

Since the code pairs in the code pair set as described above are a combination that minimizes the peak power to average power ratio, it may be assigned first from the viewpoint of the peak power to average power ratio.

의 QLS부호가 사용되는 경우 전체 부호의 개수는

개이다. 하지만 전체

개의 부호를 사용하는 경우는 시간차가 없을 때만 상호상관값이 0이 되고, 다른 시간차에서는 상호상관값이 0이 되지 않게 된다. 결국 오직 시간차가 0일 때만 직교성이 성립하게되므로, 간섭제거창이 존재하지 않게 된다. 그러나, 만일

개의 부호만 사용된다면, 유효 간섭제거창이

이 된다. 또한,

개의 부호만 사용한다면 유효 간섭제거창이

이 된다. 상기와 같이 사용하는 부호의 개수가 적을수록 유효 간섭제거창의 크기가 커지게 된다. 즉, 사 용 가능한 부호의 개수와 유효간섭제거창의 크기는 반비례관계이다. 하지만 사용하는 부호의 개수가 적은 경우에도 아무렇게나 부호를 선택하면 유효간섭제거창의 크기가 커지지 않는다. 부호개수와 유효간섭제거창의 반비례 관계를 유지하기 위해서는 앞에서 제안한 유효 직교부호 선택방법에 의해 선택하여야 성능이 보장된다. 상기의 부호쌍 집합은 위와 같이 유효 간섭제거창기준으로 분류되었다.The above code pair sets are classified based on the effective interference cancellation window. That is, the length of the QLS code

If the QLS code of is used, the total number of

Dog. But full

In the case of using two signs, the cross-correlation value becomes zero only when there is no time difference, and the cross-correlation value does not become zero in another time difference. After all, orthogonality is established only when the time difference is zero, so that there is no interference cancellation window. However, if

If only two symbols are used, the effective interference cancellation window is

Becomes Also,

If only two symbols are used, the effective interference canceling window

Becomes The smaller the number of codes used as described above, the larger the size of the effective interference cancellation window. That is, the number of usable codes and the size of the effective interference cancellation window are inversely related. However, even if the number of codes used is small, the size of the effective interference elimination window does not increase if the code is selected at any cost. In order to maintain the inverse relationship between the number of codes and the effective interference cancellation window, the performance must be selected by the effective orthogonal code selection method proposed above. The code pair set is classified as an effective interference cancellation window criteria as above.

In more detail, the allocation process is selected once in a code pair set order, and then a code pair is allocated in each code pair set.

내의 부호쌍들 중에서 부호를 할당한 후, 부호 쌍 집합

내의 모든 부호쌍들을 할당하여 더 이상 할당할 부호쌍이 없는 경우에 두 번째 부호쌍 집합

을 선택한 후

내의 부호쌍들 중에서 부호쌍을 할당한다.First set of sign pairs

After assigning a code among the code pairs in the code set,

The second set of code pairs if all the code pairs within are assigned and there are no more code pairs to assign.

After selecting

Allocate a code pair among the code pairs in the table.

), 네 번째(

), ...부호쌍 집합에도 상기의 부호쌍 할당방식이 동일하게 적용된다.The third time after

), fourth(

The same applies to the code pair assignment scheme.

The code assignment by the above method minimizes the peak-to-average power ratio, and when the number of channels used is small and the code set has a small number of code assignments, the length of the effective interference cancellation window is the length of the effective interference cancellation window of the corresponding code set. The length of the effective interference cancellation window is increased compared to the case of assigning codes out of order.                     

** Sequential Allocation Method of QLS Code (1-Yes)

An example of applying the above-described allocation method of the QLS code is as follows. As the simplest example, when assigning a code pair in each set of code pairs, they are allocated in ascending order. That is, the order of allocation of (I _branch code, Q _branch code) or (Q _branch code, I _branch code) is as follows:

Assign them in order. Therefore, as shown in FIG. 2 or FIG. 3, the code assignment method minimizes the peak-to-average power ratio when the codes are assigned to the I and Q components. In addition, in the sequential allocation method, the number of channels used is small.

While inside, the effect of increasing the length of the effective interference elimination window is obtained.

** Sequential allocation method of QLS code (2)

This method is a sequential allocation method for obtaining the effect of improving the cross-correlation property of the QLS code. The code pairs of the I component code and the Q component code are classified into a code pair set as follows, and then the code pairs are allocated.

이라 할 때 부호쌍 집합을 다음과 같이 정의 할 수 있다.
First, a set of valid orthogonal codes selected according to the orthogonal code selection method

In this case, a set of code pairs can be defined as follows.

또는

= {(Code_left , Code_right)

(Code_left, Code_right)=(I_branch부호,Q_branch부호) 또는 (Q_branch부호,I_branch부호)} (단,Q=

)

or

= {(Code _left , Code _right )

(Code _left , Code _right ) = (I _branch sign, Q _branch sign) or (Q _branch sign, I _branch sign)} (Q =

)

After that, the code pairs are allocated within the set of code pairs.

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉,

은 초기집합으로서 위와 같이 별도로 정의된다. However, generalized code pair set display

Is

end

Can only be displayed when

In other words,

Is an initial set and is separately defined as above.

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의된다. Also, generalized code pair set display

Is

end

Can only be displayed when

If

Is an initial set and is separately defined as above.

Based on the orthogonal code selection method, code pairs between the I component code and the Q component code are classified into a code pair set as described above. A code pair is then assigned in the code pair set, and any code in the code pair set may be assigned first. That is, the code pairs in the same set of code pairs may be assigned first.

In more detail, once a code pair set is selected in a code pair set order, a code pair is allocated in each code pair set.

내의 부호쌍들 중에서 부호쌍을 할당한 후, 부호쌍 집합

내의 모든 부호쌍들을 할당하여 더 이상 할당할 부호쌍이 없는 경우에 두 번째 부호쌍 집합

을 선택한 후

내의 부호쌍들 중에서 부호쌍을 할당한다.First set of sign pairs

After assigning a code pair among the code pairs in the code pair,

The second set of code pairs if all the code pairs within are assigned and there are no more code pairs to assign.

After selecting

Allocate a code pair among the code pairs in the table.

), 네 번째(

), ...부호쌍 집합에도 상기의 부호쌍 할당방식이 동일하게 적용된다. The third time after

), fourth(

The same applies to the code pair assignment scheme.

들에서 모든 부호쌍을 할당한 경우, 다음으로 부호쌍

들에서 부호쌍을 부호쌍 집합

들에서와 같은 방법을 적용하여 할당한다.A set of sign pairs

If you assigned all code pairs in the

Set of sign pairs

Assign them in the same way as in the above.

와

들의 순서를 바꾸어도 같은 효과를 얻을 수 있다.Also set of code pairs

Wow

You can achieve the same effect by changing their order.

내의 부호쌍들 중에서 부호쌍을 할당한 후, 부호쌍 집합

내의 모든 부호쌍들을 할당하여 더 이상 할당할 부호쌍이 없는 경우에 두 번째 부호쌍 집합

을 선택한 후

내의 부호쌍들 중에서 부호쌍을 할당한다.That is, first set of sign pairs

After assigning a code pair among the code pairs in the code pair,

The second set of code pairs if all the code pairs within are assigned and there are no more code pairs to assign.

After selecting

Allocate a code pair among the code pairs in the table.

), 네 번째(

),...부호쌍집합에도 상기의 부호쌍 할당방식이 동일하게 적용된다. 그 후 부호쌍 집합

들에서 모든 부호쌍을 할당한 경우, 다음으로 부호쌍 집합

들에서 부호쌍을 부호쌍 집합

들에서와 같은 방법을 적용하여 할당한다.The third time after

), fourth(

The same applies to the code pair assignment scheme. A set of sign pairs

If all code pairs have been assigned from the

Set of sign pairs

Assign them in the same way as in the above.

들에서만 이루어지거나, 부호집합

들에서만 이루어지는 동안은 시간차가 +1,-1 일 때 완벽하게 직교성질을 만족하게 되는 효과를 얻게 된다.Therefore, the code assignment according to the above method requires a small number of channels to be used.

, Or set of symbols

While only in the field, when the time difference is + 1, -1, the orthogonality is completely satisfied.

In addition, the code allocation by the above method is effective interference elimination window when the number of channels is used in the code set with a small number of effective interference elimination window is applied to the length of the effective interference elimination window of the corresponding code set compared to the case of assigning codes out of order The effect of increasing the length of the removal window is obtained.

** Sequential allocation method of QLS code (2-Yes)

An example of applying the above-described allocation method of the QLS code is as follows. As the simplest example, when assigning a code pair in each set of code pairs, assign them in ascending order. That is, assign order of (I _branch code, Q _branch code) or (Q _branch code, I _branch code)

or

Assign them in order.

In the sequential allocation method described above, the number of channels to be used is small so that the code allocation

or

While it is inside, even when the time difference is +1, -1, the orthogonal property is completely satisfied.

Fourth, the case of the spreading method of allocating the same code to the I component and the Q component as shown in FIG.

** Sequential allocation method of QLS code (3)

This method is a sequential allocation of QLS codes to increase the length of the effective interference cancellation window.                     

이라 할 때, 부호 집합들은 다음과 같이 정의한다.First, a set of valid orthogonal codes selected according to the orthogonal code selection method

In this case, the code sets are defined as follows.

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의된다.Generalized code set representation

Is

end

Can only be displayed when

If

Is an initial set and is separately defined as above.

Any code in the code set may be assigned first. That is, the codes in the same code set may be assigned to any one first.

In more detail, once a code set is selected in the code set order, a code is assigned in each code set.

내의 부호들 중에서 부호를 할당한 후, 부호 집합

내의 모든 부호들을 할당하여 더 이상 할당할 부호가 없는 경우에 두 번째 부호집합

을 선택한 후

내의 부호들 중에서 부호를 할당한다.First set of symbols

Code set after allocating code among codes in

All symbols in the second set of codes if no more signs are assigned

After selecting

The code is assigned among the signs in the code.

), 네 번째(

), ...부호집합에도 상기의 부호 할당방식이 동일하게 적용된다. The third time after

), fourth(

The same applies to the code set.

Therefore, the code allocation by the above method is performed when the number of channels used is small, and the code allocation is made in a code set with a small number of codes. When the length of the effective interference cancellation window is applied as the length of the effective interference cancellation window of the corresponding code set, the codes are allocated out of order. Compared with this, the length of the effective interference elimination window is increased.

** Sequential allocation method of QLS code (3-example)

An example of applying the above-described allocation method of the QLS code is as follows. As the simplest example, each code set is assigned in ascending order as it is assigned.

순서로 차례대로 할당한다.That is, the order of code assignment in the set of effective orthogonal codes selected according to the orthogonal code selection method

Assign them in order.

내에서 이루어지는 동안은 유효간섭제거창의 길이가 증가하게 되는 효과를 얻는다.
Therefore, the code assignment by the above method requires a small number of channels to be used.

While inside, the effect of increasing the length of the effective interference elimination window is obtained.

** Sequential allocation method of QLS code (4)

This method is a sequential allocation method to obtain the effect of improving the cross-correlation property of the QLS code.

이라 할 때 부호 집합

를 다음과 같이 정의할 수 있다. First, a set of valid orthogonal codes selected according to the orthogonal code selection method

The set of symbols

Can be defined as:

The code is then assigned within the code set, where the actual code set is

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의된다. Generalized code set representation

Is

end

Can only be displayed when

If

Is an initial set and is separately defined as above.

는

가

인 자연수일 때만 표시가능하며,

인 경우 즉

은 초기집합으로서 위와 같이 별도로 정의된다.Also, generalized code set representation

Is

end

Can only be displayed when

If

Is an initial set and is separately defined as above.

Based on the orthogonal code selection method, each QLS code is classified into a code set as described above. A code is then assigned in the code set, and any code in the code set may be assigned first. That is, the codes in the same code set may be assigned to any one first.                     

In more detail, once a code set is selected in the code set order, a code is assigned in each code set.

내의 부호들 중에서 부호를 할당한 후, 부호 집합

내의 모든 부호들을 할당하여 더 이상 할당할 부호가 없는 경우에 두 번째 부호집합

을 선택한 후

내의 부호들 중에서 부호를 할당한다.First set of symbols

Code set after allocating code among codes in

All symbols in the second set of codes if no more signs are assigned

After selecting

The code is assigned among the signs in the code.

), 네 번째(

), ...부호집합에도 상기의 부호 할당방식이 동일하게 적용된다. 그 후 부호집합

들에서 모든 부호를 할당한 경우, 다음으로 부호집합

들에서 부호를 부호집합

들에서와 같은 방법을 적용하여 할당한다.The third time after

), fourth(

The same applies to the code set. Then the code set

If you assign all signs in the field, then

Sets the sign in the field

Assign them in the same way as in the above.

와

들의 순서를 바꾸어도 같은 효과를 얻을 수 있다.Also code set

Wow

You can achieve the same effect by changing their order.

내의 부호들 중에서 부호를 할당한 후, 부호 집합

내의 모든 부호들을 할당하여 더 이상 할당할 부호가 없는 경우에 두 번째 부호집합

을 선택한 후

내의 부호들 중에서 부호를 할당한다.That is, first set of symbols

Code set after allocating code among codes in

All symbols in the second set of codes if no more signs are assigned

After selecting

The code is assigned among the signs in the code.

), 네 번째(

), ...부호집합에도 상기의 부호 할당방식이 동일하게 적용된다. 그 후 부호집합

들에서 모든 부호를 할당한 경우, 다음으로 부호집합

들에서 부호를 부호집합

들에서와 같은 방법을 적용하여 할 당한다.The third time after

), fourth(

The same applies to the code set. Then the code set

If you assign all signs in the field, then

Sets the sign in the field

Assign them in the same way as they do for them.

들에서만 이루어지거나, 부호집합

들에서만 이루어지는 동안은 시간차가 +1,-1일 때도 완벽하게 직교성질을 만족하게 하는 효과를 얻게 된다.Therefore, the code assignment according to the above method requires a small number of channels to be used.

, Or set of symbols

While only in the field, even when the time difference is + 1, -1, the orthogonality is satisfied.

In addition, if the number of channels used in the code allocation is made by the above method, the effective interference elimination window is applied to the length of the effective interference elimination window of the corresponding code set. The effect of increasing the length of the removal window is obtained.

** Sequential allocation method of QLS code (4-example)

An example of applying the above-described allocation method of the QLS code is as follows. In the simplest case, each code set is assigned in ascending order as it is assigned.

That is, the code assignment order is assigned in the following order.

or

또는

내에서 이루어지는 동안은 시간차 +1, -1 일 때도 완벽하게 직교성질을 만족하게 되는 효과가 있다.
Therefore, the code assignment by the above method requires less channel assignment.

or

While it is done within the time difference +1, -1 even when the orthogonal property is fully satisfied.

As described above, in the present invention, a set of orthogonal codes satisfying autocorrelation and cross-correlation characteristics among QLS codes generated by the QLS code generation method is represented by a constant QLS relation, and a set representing the orthogonal code set is an element of a constant QLS relation. The correspondence between the set of orthogonal codes and the elements of the set representing the orthogonal sets is a one-to-one correspondence in ascending order of the element numbers, so that any orthogonal code is selected so that the corresponding orthogonal code set is consistent with the orthogonal code set.

In addition, a code pair is generated using a set of orthogonal code set elements such that the selected set of orthogonal codes is a minimum 180 degree phase difference between the I and Q component codes.

Therefore, the method of assigning the same or different codes to the I component and the Q component, respectively, using the orthogonal code selection and the code pair will be described.

4 is a flowchart illustrating an embodiment of classifying a QLS code into a set of representative valid orthogonal codes.

First, the user selects the desired code length other than zero. However, the code length N has a value of 2 ^m and m is a natural number of 3 or more (steps 40, 41).

인가를 판단한다. (단계 42,43,44,45).Create a QLS code and select the code component length L _GUARD and the effective interference cancellation window length L _IFW

Determine authorization. (Steps 42,43,44,45).

이 아니면 상기 단계 43을 반복하고,

이면

를 만족하는 g를 구한다. (단계 46).As a result of the determination,

If not, repeat step 43 above.

Back side

Find g satisfying (Step 46).

After the step 46, the effective orthogonal code set classification k = 1 and the effective orthogonal code element classification j = 0 are set. (Step 47,48).                     

2^m-g +j 번째 QLS 부호를 원소로 포함 시킨다. (단계 49).the kth orthogonal code set O _k to (k-1)

Include the 2 ^mg + j th QLS code as an element. (Step 49).

를 판단하여, 성립되지 않으면 상기 단계 49를 재수행하고, 성립되면 상기 단계 47의 k값에 1을 더한다. (단계 50,51,52).1 is added to j, i.e., j + 1

If not, it repeats step 49 if not established, and adds 1 to the value k of step 47 if it is established. (Steps 50, 51, 52).

인가를 판단하여, 성립되지 않으면 상기 단계 48이하 단계를 재수행하고, 성립되면 2^g 개의 유효직교부호집합들중 한개의 집합을 선택하는 대표유효직교부호집합을 선택한다. (단계 53,54).after

The authorization is determined, and if not, the above step 48 is performed again, and if it is established, a representative valid orthogonal code set is selected which selects one set of 2 ^g valid orthogonal code sets. (Steps 53,54).

The selected effective orthogonal code set elements are mapped to the representative effective orthogonal code set elements in ascending order. (Step 55).

5 is a flowchart illustrating an embodiment of selecting a method for allocating a QLS code of a representative valid orthogonal code set.

 Referring to FIG. 4, a representative set of orthogonal codes is selected (step 60).

It is determined whether the selected effective orthogonal code set is assigned different QLS codes to the I component and the Q component, and if differently assigned (QPSK method), a peak power to average power ratio minimizing code pair combination is selected, and N / 2 of N codes. When not used below, the sequential allocation method (1) of the QLS code of the present invention is applied, and when the N / 2 or less of N numbers are used, the sequential allocation method (2) of the QLS code of the present invention is applied. (Steps 61, 62, 63, 64, 65).                     

As a result of the determination of step 61, when no other code is assigned to the I component and the Q component, the code set is classified based on the interference canceling window, and when the N / 2 or less of the N codes are used, the QLS code of the present invention The sequential allocation method (3) is applied, and when the N / 2 or less of the total codes N are used, the sequential allocation method (4) of the QLS code of the present invention is applied. (Steps 66,67,68,69).

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments.

Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

According to the present invention, in a spreading scheme in which different codes are assigned to I and Q components in spreading schemes using QLS codes, a code pair for minimizing 180 degree phase shift between codes assigned to I and Q components is provided. The proposed method improves the peak-to-average power ratio. In addition, by improving the method of assigning codes in the orthogonal code set, there is an effect of increasing the length of the effective interference cancellation window or improving the cross-correlation property.

In addition, in the spreading scheme in which the same code is assigned to the I component and the Q component, the effective interference elimination window is temporarily increased or the cross-correlation property is improved by improving the method of allocating codes in the orthogonal code set. .

Claims (8)

In assigning the QLS code, Generating an effective orthogonal code set; Selecting a representative valid orthogonal code from the set of effective orthogonal codes; Determining whether different QLS codes are assigned to the I component and the Q component; Selecting a code pair combination that minimizes the peak-to-average power ratio; QLS code allocation method characterized in that the QLS code is sequentially assigned by determining whether N / 2 or less of the total code N. The method of claim 1, further comprising: classifying the code set based on the interference cancellation window according to the determination of whether to allocate the QLS code. delete delete delete delete delete delete

Images